Toolarithm

Finance Calculator

Auto Loan Calculator

Plan payments, trade equity, taxes, and financing offers.

Plan your auto financing

Trace the purchase, cash, and loan balance.

Purchase and primary offer

No exchange conversion. JPY rounds to whole yen.

Use the fixed contract interest rate, not a fee-inclusive APR. Terms support 1 through 120 whole months. Cash-down percentages use the price before rebates. Rebates cap at vehicle price, and actual cash down caps at the remaining financed bill.

Trade-in and existing debt

Trade equity is the allowance less the payoff quote. Positive equity reduces the financed bill; any excess is a modeled refund. Rolling a shortfall increases new debt and interest. Use a current payoff quote, which can differ from the statement balance.

Tax and fee assumptions

Rate mode adds taxable fees before any selected trade or rebate deduction and floors the tax base at zero. A trade deduction uses the full allowance, not equity after payoff. These switches are assumptions, not a tax-location lookup; use quoted tax for rules this model cannot represent.

Extra principal payments

Zero keeps the extra ongoing.

The window includes both ends. Regular payments come first, then recurring extras, then the one-time offer. Each actual payment caps at the remaining debt, and the regular payment is not recast.

Your primary financing plan

Regular monthly payment
$563.55
Amount financed
$27,630.00
Total interest
$6,182.90
Net cash at purchase
$4,000.00
First actual payment
$563.55
Final actual payment
$563.45

Payoff: 60  months60\;\text{months}; Dec 2031.

Trace the transaction funding

Applied rebate
$0.00
Unused offered rebate
$0.00
Signed trade equity
$3,000.00
Sales tax
$2,030.00
All fees
$600.00
Out-the-door purchase amount
$34,630.00
Cash down actually applied
$4,000.00
Unused cash-down offer
$0.00
Tax paid upfront
$0.00
Fees paid upfront
$0.00
Old debt settled in cash
$0.00
Excess equity refund
$0.00

Taxable base: $29,000.00

Out-the-door amount excludes trade payoff and financing interest. Net cash at purchase is actual cash down plus upfront fees, tax and any cash-settled shortfall, less an excess-equity refund.

Compare with regular payments only

Interest saved with extras: $0.00.

Time saved: 0  months0\;\text{months}.

Total loan payments: $33,812.90.

Net purchase cash plus loan payments: $37,812.90.

Net personal cash excludes the noncash value of the traded vehicle. It is not the vehicle's full economic ownership cost; insurance, fuel, maintenance and depreciation are outside this estimate.

First-month balance calculation

B1=27630+189.96−563.55=27256.41B_1=27630+189.96-563.55=27256.41

Inputs saved with this plan

Currency
USD
Vehicle price entered
32000
Cash down entry
amount
Cash down offered
4000
Primary rebate offered
0
Trade-in enabled
true
Trade allowance
3000
Old loan payoff quote
0
Negative equity treatment
finance
Tax entry
percent
Tax rate percent
7
Trade allowance reduces tax base
true
Rebate reduces tax base
false
Finance tax
true
Taxable fees
0
Non-taxable fees
600
Finance fees
true
Primary contract rate percent
8.25
Primary whole-month term
60
Extra monthly principal
0
Extra starts in month
1
Extra ends; zero means ongoing
0
One-time principal
0
One-time month
1
First payment month
2027-01
Alternative offer enabled
false

Primary monthly repayment schedule

Every primary-plan payment is included. Scroll horizontally on a small screen; all primary and alternative ledgers are available in CSV.

Full primary auto repayment ledger
Payment monthOpeningInterestRegular paidExtra paidOne-time paidTotal paidPrincipal repaidClosing
Jan 2027 (1)$27,630.00$189.96$563.55$0.00$0.00$563.55$373.59$27,256.41
Feb 2027 (2)$27,256.41$187.39$563.55$0.00$0.00$563.55$376.16$26,880.25
Mar 2027 (3)$26,880.25$184.80$563.55$0.00$0.00$563.55$378.75$26,501.50
Apr 2027 (4)$26,501.50$182.20$563.55$0.00$0.00$563.55$381.35$26,120.15
May 2027 (5)$26,120.15$179.58$563.55$0.00$0.00$563.55$383.97$25,736.18
Jun 2027 (6)$25,736.18$176.94$563.55$0.00$0.00$563.55$386.61$25,349.57
Jul 2027 (7)$25,349.57$174.28$563.55$0.00$0.00$563.55$389.27$24,960.30
Aug 2027 (8)$24,960.30$171.60$563.55$0.00$0.00$563.55$391.95$24,568.35
Sep 2027 (9)$24,568.35$168.91$563.55$0.00$0.00$563.55$394.64$24,173.71
Oct 2027 (10)$24,173.71$166.19$563.55$0.00$0.00$563.55$397.36$23,776.35
Nov 2027 (11)$23,776.35$163.46$563.55$0.00$0.00$563.55$400.09$23,376.26
Dec 2027 (12)$23,376.26$160.71$563.55$0.00$0.00$563.55$402.84$22,973.42
Jan 2028 (13)$22,973.42$157.94$563.55$0.00$0.00$563.55$405.61$22,567.81
Feb 2028 (14)$22,567.81$155.15$563.55$0.00$0.00$563.55$408.40$22,159.41
Mar 2028 (15)$22,159.41$152.35$563.55$0.00$0.00$563.55$411.20$21,748.21
Apr 2028 (16)$21,748.21$149.52$563.55$0.00$0.00$563.55$414.03$21,334.18
May 2028 (17)$21,334.18$146.67$563.55$0.00$0.00$563.55$416.88$20,917.30
Jun 2028 (18)$20,917.30$143.81$563.55$0.00$0.00$563.55$419.74$20,497.56
Jul 2028 (19)$20,497.56$140.92$563.55$0.00$0.00$563.55$422.63$20,074.93
Aug 2028 (20)$20,074.93$138.02$563.55$0.00$0.00$563.55$425.53$19,649.40
Sep 2028 (21)$19,649.40$135.09$563.55$0.00$0.00$563.55$428.46$19,220.94
Oct 2028 (22)$19,220.94$132.14$563.55$0.00$0.00$563.55$431.41$18,789.53
Nov 2028 (23)$18,789.53$129.18$563.55$0.00$0.00$563.55$434.37$18,355.16
Dec 2028 (24)$18,355.16$126.19$563.55$0.00$0.00$563.55$437.36$17,917.80
Jan 2029 (25)$17,917.80$123.18$563.55$0.00$0.00$563.55$440.37$17,477.43
Feb 2029 (26)$17,477.43$120.16$563.55$0.00$0.00$563.55$443.39$17,034.04
Mar 2029 (27)$17,034.04$117.11$563.55$0.00$0.00$563.55$446.44$16,587.60
Apr 2029 (28)$16,587.60$114.04$563.55$0.00$0.00$563.55$449.51$16,138.09
May 2029 (29)$16,138.09$110.95$563.55$0.00$0.00$563.55$452.60$15,685.49
Jun 2029 (30)$15,685.49$107.84$563.55$0.00$0.00$563.55$455.71$15,229.78
Jul 2029 (31)$15,229.78$104.70$563.55$0.00$0.00$563.55$458.85$14,770.93
Aug 2029 (32)$14,770.93$101.55$563.55$0.00$0.00$563.55$462.00$14,308.93
Sep 2029 (33)$14,308.93$98.37$563.55$0.00$0.00$563.55$465.18$13,843.75
Oct 2029 (34)$13,843.75$95.18$563.55$0.00$0.00$563.55$468.37$13,375.38
Nov 2029 (35)$13,375.38$91.96$563.55$0.00$0.00$563.55$471.59$12,903.79
Dec 2029 (36)$12,903.79$88.71$563.55$0.00$0.00$563.55$474.84$12,428.95
Jan 2030 (37)$12,428.95$85.45$563.55$0.00$0.00$563.55$478.10$11,950.85
Feb 2030 (38)$11,950.85$82.16$563.55$0.00$0.00$563.55$481.39$11,469.46
Mar 2030 (39)$11,469.46$78.85$563.55$0.00$0.00$563.55$484.70$10,984.76
Apr 2030 (40)$10,984.76$75.52$563.55$0.00$0.00$563.55$488.03$10,496.73
May 2030 (41)$10,496.73$72.17$563.55$0.00$0.00$563.55$491.38$10,005.35
Jun 2030 (42)$10,005.35$68.79$563.55$0.00$0.00$563.55$494.76$9,510.59
Jul 2030 (43)$9,510.59$65.39$563.55$0.00$0.00$563.55$498.16$9,012.43
Aug 2030 (44)$9,012.43$61.96$563.55$0.00$0.00$563.55$501.59$8,510.84
Sep 2030 (45)$8,510.84$58.51$563.55$0.00$0.00$563.55$505.04$8,005.80
Oct 2030 (46)$8,005.80$55.04$563.55$0.00$0.00$563.55$508.51$7,497.29
Nov 2030 (47)$7,497.29$51.54$563.55$0.00$0.00$563.55$512.01$6,985.28
Dec 2030 (48)$6,985.28$48.02$563.55$0.00$0.00$563.55$515.53$6,469.75
Jan 2031 (49)$6,469.75$44.48$563.55$0.00$0.00$563.55$519.07$5,950.68
Feb 2031 (50)$5,950.68$40.91$563.55$0.00$0.00$563.55$522.64$5,428.04
Mar 2031 (51)$5,428.04$37.32$563.55$0.00$0.00$563.55$526.23$4,901.81
Apr 2031 (52)$4,901.81$33.70$563.55$0.00$0.00$563.55$529.85$4,371.96
May 2031 (53)$4,371.96$30.06$563.55$0.00$0.00$563.55$533.49$3,838.47
Jun 2031 (54)$3,838.47$26.39$563.55$0.00$0.00$563.55$537.16$3,301.31
Jul 2031 (55)$3,301.31$22.70$563.55$0.00$0.00$563.55$540.85$2,760.46
Aug 2031 (56)$2,760.46$18.98$563.55$0.00$0.00$563.55$544.57$2,215.89
Sep 2031 (57)$2,215.89$15.23$563.55$0.00$0.00$563.55$548.32$1,667.57
Oct 2031 (58)$1,667.57$11.46$563.55$0.00$0.00$563.55$552.09$1,115.48
Nov 2031 (59)$1,115.48$7.67$563.55$0.00$0.00$563.55$555.88$559.60
Dec 2031 (60)$559.60$3.85$563.45$0.00$0.00$563.45$559.60$0.00

Model: fixed contract interest, equal monthly periods, end-of-month payments and half-up currency rounding. The scheduled payment is the smallest currency-unit amount clearing the rounded ledger by the term; a once-rounded annuity formula may differ. Rebates, taxes, financed fees and trade payoff are explicit assumptions. No daily accrual, precomputed-interest contract, balloon balance, ownership expenses, prepayment penalty or recasting. Offer comparisons do not discount cash flows for time value.

What Can You Create?

Build a vehicle financing plan you can reconcile

A payment from the full transaction

Begin with the negotiated vehicle price and trace rebates, tax, fees, trade payoff and cash down into the financed balance. A complete funding breakdown makes a quoted monthly payment easier to assess against the agreement behind it.

A transparent trade-in scenario

Separate an allowance from the debt still attached to the old vehicle. Compare paying a shortfall in cash with adding it to the new loan, and keep excess positive equity or unused cash-down offers visible.

A rate-versus-rebate comparison

Recalculate a second offer with its own contract rate, whole-month term and replacement rebate. Compare monthly commitment, interest and net personal cash while holding the vehicle, trade and other transaction assumptions consistent.

Auto loan formulas and a step-by-step example

Trade equity uses the allowance VV and old-loan payoff OO. A negative result is an old debt shortfall, which must be settled in cash or included in the new financing.

E=V−O,E+=max⁡(E,0),E−=max⁡(−E,0)E=V-O,\qquad E_+=\max(E,0),\qquad E_-=\max(-E,0)

In estimated-tax mode, vehicle price, taxable fees and the selected deductions determine the base. The deduction switches are explicit assumptions. They do not select a jurisdiction or imply that every dealer rebate or trade qualifies.

Btax=max⁡(0,H+Ftaxable−Rdeductible−Vdeductible),T=round⁡currency ⁣(Btaxt100)B_{\text{tax}}=\max(0,H+F_{\text{taxable}}-R_{\text{deductible}}-V_{\text{deductible}}),\qquad T=\operatorname{round}_{\text{currency}}\!\left(B_{\text{tax}}\frac{t}{100}\right)

Step 1: Reconcile a negative-equity trade

Suppose a vehicle costs 20,000 dollars and the primary offer includes a 1,000-dollar rebate. Your old vehicle receives a 5,000-dollar allowance but has a 7,000-dollar payoff quote. The signed equity is negative 2,000 dollars. In this example that shortfall is financed.

E=5000−7000=−2000,E−=2000E=5000-7000=-2000,\qquad E_-=2000

Step 2: Calculate tax and opening principal

Assume a 6%6\% tax on price less the full trade allowance, with the rebate not reducing tax. Tax is 900 dollars. Add 500 dollars of non-taxable financed fees and subtract 2,000 dollars of actual cash down; the opening loan becomes 20,400 dollars.

T=(20000−5000)⋅0.06=900T=(20000-5000)\cdot0.06=900P=20000−1000+900+500+2000−2000=20400P=20000-1000+900+500+2000-2000=20400

The out-the-door purchase amount is also 20,400 dollars here, but that equality is a coincidence: the cash down and old shortfall offset. Out-the-door price excludes trade payoff and interest, whereas principal follows how the whole transaction is funded.

Step 3: Calculate and inspect monthly payments

With an illustrative zero-interest term of 24 months, the scheduled payment is 850 dollars. A first-month extra of 100 dollars makes the loan payment 950 dollars and leaves 19,450 dollars. At a positive rate, interest is rounded before each payment is applied.

M=2040024=850,B1=20400−850−100=19450M=\frac{20400}{24}=850,\qquad B_1=20400-850-100=19450

For opening principal PP, numerical annual contract percentage aa, monthly rate rr and term NN, the unrounded annuity relationship is:

r=a1200,M={Pr1−(1+r)−N,r>0PN,r=0r=\frac{a}{1200},\qquad M=\begin{cases}\dfrac{Pr}{1-(1+r)^{-N}},&r>0\\[6pt]\dfrac{P}{N},&r=0\end{cases}

This tool searches currency units against the rounded monthly ledger, so the actual regular payment may differ slightly from rounding that formula once. Extra payments are applied only when scheduled, and no payment can create a negative debt balance.

Ik=round⁡currency(Bk−1r),Bk=Bk−1+Ik−actual loan paymentkI_k=\operatorname{round}_{\text{currency}}(B_{k-1}r),\qquad B_k=B_{k-1}+I_k-\text{actual loan payment}_k

Compare complete offers using net personal purchase cash plus loan payments, with signed trade equity shown separately. Because the same trade assumption is used in both offers, its noncash contribution does not disappear from the funding reconciliation. Ongoing ownership expenses and the time value of money are outside the comparison.

Why Users Love This Tool

Understand what changes the amount financed

Keep the cash components distinct

  • Trade payoff affects net equity while a selected tax deduction uses the full allowance.
  • Taxable and non-taxable fees are entered separately, with financing or upfront payment choices.
  • Rebates cap at the vehicle price, and applied cash down caps at the remaining financed bill.
  • Monthly interest and monetary inputs use explicit half-up currency rounding.

Compare within clear boundaries

  • Exact whole-month terms avoid silently rounding fractional repayment periods.
  • The same dated extra-payment policy applies independently to each offer.
  • Net personal cash is separated from the noncash trade asset and ongoing ownership expenses.
  • Quoted tax can replace the simplified taxable-base switches when a real transaction needs it.
Perfect For

Useful for vehicle shopping and repayment planning

Buyers reviewing a dealer worksheet

Reconcile the purchase price, fees, rebate, allowance and payoff before focusing on the monthly number. Match the transaction funding with the amount financed on a written agreement, and question differences instead of hiding them inside a longer term.

Drivers replacing a financed vehicle

Use a current payoff quote for the vehicle being traded and inspect whether the new loan includes an old shortfall. Keep cash settlement and financed settlement as different scenarios, because their first-day cash needs and future interest can differ.

Borrowers testing extra principal

Schedule a recurring increase or one-time contribution and inspect the final payment and payoff date. Check how your lender applies extra money and whether the contract uses daily or precomputed interest before relying on the modeled savings.

How It Works

How it works in three quick steps.

1

Enter the negotiated vehicle price and loan terms

Set the vehicle price, offered cash down, primary rebate, fixed contract interest rate and exact whole-month term. Choose a display currency and the first payment month.

2

Reconcile trade equity, tax and fee funding

If trading a vehicle, enter both its allowance and current payoff quote. Choose how to settle negative equity. Enter quoted tax or explicit taxable-base assumptions and decide whether tax and fees are financed.

3

Compare offers and save the complete plan

Add dated extra principal payments and optionally compare a second rate, term and rebate. Inspect transaction funding and monthly balances, then copy, share, download CSV or print the primary schedule.

Download & Print

Save the transaction and every repayment row

CSV for the enabled offers

Export primary and optional alternative funding, plus selected and regular-only schedules for each offer. Source settings retain their entered precision, and signed trade equity and refunds remain signed numeric amounts for spreadsheet review.

Primary-plan print and PDF

Print the primary schedule in landscape or use Save as PDF. The layout retains results, transaction assumptions and all primary payment rows while removing editing controls and supporting sections. Alternative ledgers remain available in the CSV download.

Copy or share an editable plan

Copy the result summary or save a settings link that reopens the scenario. Link fragments contain readable financial values. Keep personal examples private and retain actual lender and dealer documents when using an estimate to compare quoted terms.

FAQ

Frequently Asked Questions

How does the auto loan calculator calculate a payment?
The calculator first reconciles the vehicle price, applied rebate, trade equity, taxes, fees and actual cash down to determine the financed balance. It then uses a fixed-rate monthly ledger with half-up currency rounding. The regular payment is the smallest currency-unit amount that repays that rounded ledger by your chosen term. The final actual payment is capped at the amount owed, so it can be smaller.
How is negative equity in a trade-in handled?
Trade equity is the allowance for your current vehicle less its existing loan payoff quote. If the result is negative, choose whether the shortfall is added to the new loan or paid separately in cash. Financing it increases new debt and the balance on which interest accrues. The shortfall stays visible in the funding breakdown rather than being disguised as a smaller vehicle price or an unexplained fee.
Does the trade-in tax deduction use value or equity?
When enabled in rate mode, this model deducts the full trade allowance from the taxable base, not the equity remaining after the old loan is settled. Your payoff quote changes funding but does not change that modeled tax deduction. Actual eligibility and limits depend on the transaction and jurisdiction. Turn the deduction off or use a quoted tax amount when the selected assumptions do not match the applicable rules.
Do rebates always reduce the sales tax?
No automatic assumption is made. The rebate reduces the vehicle purchase amount, but it reduces the rate-based taxable base only when you enable that switch. Taxable dealer or add-on fees enter the base before deductions, while non-taxable fees do not. Rebates are capped at the vehicle price in each offer. These are explicit modeling choices, so use a written tax quote for rules or exemptions the switches cannot represent.
What if my cash down or trade equity is more than needed?
Actual cash down is capped at the remaining financed bill after the rebate and positive trade equity are applied. Unused cash-down offers remain visible and are not treated as money spent. Excess positive trade equity becomes a modeled refund. Net cash at purchase subtracts that refund from gross cash requirements and can be negative. Confirm the real settlement treatment with the dealer rather than assuming every excess amount will be returned automatically.
How do financed taxes and fees change the result?
Financed tax and fees become part of the opening loan balance and therefore accrue interest. Paying them upfront moves those amounts to the purchase cash requirement instead. The out-the-door purchase amount includes applied rebate, all entered fees and tax but excludes trade payoff and loan interest. This separation lets you see whether a lower monthly payment is accompanied by a larger cash payment at the transaction.
Can I compare a rebate with a promotional interest rate?
Enable the alternative financing offer and enter its replacement rate, term and rebate. The calculator rebuilds funding and tax for that offer using the same vehicle price, trade, cash-down offer, fee settings and extra-payment policy. Compare both monthly payments and net personal cash across the completed plans. The comparison does not discount payment timing, estimate investment returns, verify promotion eligibility, or include insurance and other ownership expenses.
How are recurring and one-time extra payments applied?
The regular monthly payment is applied first, followed by the recurring extra during its inclusive start and end window, then the one-time offer in its chosen month. An ending month of zero keeps the recurring extra ongoing. Every actual amount is capped at debt still owed. The regular payment is not recast, and extras scheduled after an offer is already paid off have no effect on that offer.
Should I enter the interest rate or APR from the disclosure?
Use the contract interest rate that accrues on the loan balance. A fee-inclusive APR can differ from that rate, so using it while also entering financing charges may count part of the cost twice. This tool uses equal monthly periods and a fixed rate, rather than recreating daily accrual or a precomputed-interest contract. Review the lender's disclosure for the actual amount financed, payment schedule, APR and applicable charges.
Can I export both offers and their complete schedules?
CSV includes funding for each enabled offer and its selected-payment and regular-only ledgers, together with active inputs at their entered precision. Print retains the primary offer's complete monthly schedule; choose landscape and Save as PDF for the wide table. Copy records the assumptions, and sharing restores editable settings from the link fragment. Anyone holding that link can read the financial inputs, so protect personal scenarios when saving or distributing them.
About This Tool

About this vehicle purchase and financing planner

A vehicle payment can conceal several separate decisions. The negotiated price determines only part of the transaction; a rebate, trade allowance, old loan payoff, tax and fees can all change how much is borrowed. Toolarithm's Auto Loan Calculator starts with those components and follows them into a complete monthly repayment record. It keeps the purchase amount, financed balance and cash needed at the transaction distinct, so a lower monthly figure does not automatically look like a less expensive or less demanding purchase.

Trade equity deserves particular attention because an old vehicle can contribute an asset or bring an unresolved debt shortfall into the replacement transaction. The calculator preserves that sign and lets you choose whether negative equity is financed or settled in cash. It also distinguishes unused cash-down offers from cash actually applied and displays excess positive equity as a modeled refund. These details provide a clearer reconciliation than subtracting a trade allowance without considering the debt still attached to it.

The optional second offer supports comparisons such as a replacement rebate against a different contract rate or repayment term. It recalculates funding rather than merely changing the interest percentage on an unchanged balance. Both offers use the same entered transaction and extra-payment assumptions, while their completed cash totals remain undiscounted. The model is intended for fixed-rate monthly planning and does not reproduce every tax rule, lender contract, or daily payoff calculation. Verify the written price, tax treatment, amount financed and repayment terms with the parties to the transaction, and budget separately for insurance, fuel, maintenance and the vehicle's changing value.

Editorial Transparency

Who maintains this page

Ownership and review

Written and maintained by the Toolarithm editorial team. No review date is shown without a maintained editorial record. No independent professional review is claimed.

Methodology

Formulas are checked with worked examples and boundary cases. Timing, compounding, payment, and rounding assumptions remain visible; results are educational estimates, not financial advice.

Read the editorial methodology

Dates and sources

Review dates change only after a substantive method or content check.

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