OTD Price vs Monthly Payment Checker

First, it calculates OTD price = selling price + dealer fees + taxes. Then it computes the amount financed = OTD price − down payment. Using APR and term, it calculates the standard amortized monthly payment (or uses a zero-interest shortcut if APR = 0), and finally totals everything: total paid = (monthly payment × term) + down payment.

Monthly payments can look close even when the deal is expensive because interest over a long term and financeability of fees can drive up total paid. High dealer fees (relative to the selling price), higher APR, and longer loan terms can all make the total cost jump while the monthly figure stays “in range.” This tool assumes fixed APR for the full term and treats taxes as a single upfront amount.

If your down payment exceeds the OTD total, the calculator can’t compute the loan correctly and will block the result—double-check those numbers. The “caution/high concern” alerts are heuristics: they help you spot potentially padded quotes, but they don’t replace a full review of the purchase order (including add-ons not included in your entries). The calculator excludes items like registration/title, insurance, maintenance, and fuel, and assumes no trade-in negative equity or incentives unless you included them in the selling price.

With APR = 0, it uses the zero-interest payment formula so interest cost doesn’t artificially appear. If you enter a very large down payment, the loan amount shrinks and monthly payment drops, but total paid still may remain high if fees/taxes are elevated. If dealer fees are a large share of the selling price, the tool will flag the deal since that often signals padding or costly add-ons.