Calculate monthly loan payments, total interest charges, and repayment splits with our free Loan Calculator. Evaluate personal loans, auto loans, and student financing across flexible term horizons with 100% offline privacy.
Input your total loan principal amount in dollars and annual interest rate percentage.
Choose repayment duration in months or click quick term preset pills (36m, 48m, 60m, 72m, 120m, 360m).
Instantly view estimated monthly payment, total interest charges, total repayment cost, and principal vs interest ratio.
Your financial figures are processed entirely inside your browser using client-side JavaScript. Nothing ever travels over a network to any server — making BunchTool 100% private.
Calculations run locally in real time as you adjust inputs. Monthly payment amounts and total interest costs update instantly without page reloads.
Visual breakdown bar illustrating the exact percentage of your total payments going toward borrowing cost (interest) vs loan balance (principal).
Amortized Loan Payments ensure equal monthly installments throughout the loan term, where each payment is partitioned between interest charges and principal reduction.
The mathematical equation for calculating monthly loan payments is:
\(M = P \times \frac{r(1 + r)^n}{(1 + r)^n - 1}\)
Where \(P\) is loan principal, \(r\) is monthly interest rate (\(\text{annual APR} \div 12 \div 100\)), and \(n\) is loan duration in months.
Choosing a longer loan term reduces your mandatory monthly payment, but increases cumulative interest paid over time. Comparing term options helps balance monthly affordability against lifetime costs.