Tool: Auto loan calculator · Embed · All how-we-calculate pages · Questions
Purpose
Estimate a fixed monthly payment for a vehicle purchase from price, cash down, trade-in, optional sales tax and fees you type, sample APR, and term in months. Educational only.
Amount financed
- Tax base:
max(0, vehiclePrice − tradeIn) - Sales tax:
taxBase × (salesTaxPercent / 100) -
Amount financed:
max(0, vehiclePrice + salesTax + fees − downPayment − tradeIn)
Payment formula
For principal P, monthly rate r = APR/12/100, and n months:
payment = P · r · (1+r)^n / ((1+r)^n − 1) when r > 0; otherwise P / n.
Optional extra monthly payment is added to the base payment and applied as extra principal each month in the schedule.
What we intentionally leave out
- Live dealer rates, credit scores, and approval decisions
- State tax tables, title/registration lookups, and negative equity roll-ins beyond your inputs
- Extended warranties, GAP, insurance, and dealer add-ons (unless you put them in fees)
- Variable rates and balloon payments
Related
Last reviewed: August 9, 2026.
YMYL notice: This site is for education only. It is not financial, tax, or investment advice. Nestfigure is not a bank, credit union, broker, investment adviser, or fiduciary. Product terms, rates, and penalties vary—always read your institution’s disclosures before acting. Calculator results are mathematical estimates, not bank quotes.