Free loan amortization schedule with monthly principal & interest breakdown. See total interest and how extra payments reduce payoff time—Calculator4U.
Calculate your loan amortization schedule with a full principal and interest breakdown for any loan type.
An amortization calculator generates a complete payment-by-payment schedule for any fixed-rate loan, showing exactly how much of each payment goes toward interest versus reducing your principal balance. Enter your loan amount, interest rate, and term to instantly see your monthly payment, total interest paid, and a full amortization table — plus the impact of extra payments on your payoff date and total interest cost.
How to use this amortization calculator:
Why the amortization schedule matters: Most borrowers are surprised to learn that in the early years of a 30-year mortgage, the majority of each payment goes toward interest — not reducing the loan balance. On a $400,000 mortgage at 6.5%, the very first payment of $2,528 applies only $361 to principal and $2,167 to interest. By year 10, that split shifts to roughly $640 principal / $1,888 interest. By year 25, it flips entirely: $1,900+ goes to principal and less than $628 to interest. The amortization table makes this visible row by row.
The power of extra payments: Because early payments are so heavily interest-weighted, any extra principal payment made early in a loan skips multiple interest-heavy rows on the amortization schedule. Adding just $100/month extra on a 30-year $400,000 mortgage at 6.5% saves approximately $45,000 in interest and cuts nearly 5 years off the loan term. Adding $500/month saves roughly $113,000 and shortens the term by about 10 years. Use the extra payment fields to model your exact savings.
This calculator works for mortgages, auto loans, and personal loans. It is designed for fixed-rate, fully amortizing loans. It does not account for adjustable-rate mortgages (ARMs), interest-only loans, or balloon payment loans, which have non-standard amortization structures.
An amortization schedule is a complete table of every loan payment showing how each installment is split between principal (reducing your balance) and interest (the lender's fee). Early in the loan, most of each payment goes to interest. Over time, the split shifts in your favour. For a 30-year $400,000 mortgage at 6.5%, the first payment of ~$2,528 contains ~$2,167 in interest and only ~$361 in principal.
On a $400,000 mortgage at 6.5% for 30 years, total interest paid is approximately $510,177 — more than the original loan. At 7.0%, total interest rises to ~$558,036. This is why extra principal payments made early in the loan can save tens of thousands of dollars: they skip multiple rows of the amortization schedule that are otherwise dominated by interest charges.
Extra payments go 100% toward your principal, immediately reducing future interest charges. On a 30-year $400,000 mortgage at 6.5%: adding $100/month extra saves ~$45,000 in interest and cuts ~4 years 8 months off the term. Adding $500/month saves ~$113,000 and shortens the loan by ~10 years. The earlier you make extra payments, the greater the compounding effect — use the calculator to model your exact savings.
On a $400,000 loan: a 30-year mortgage at 6.5% costs ~$2,528/month with ~$510,177 in total interest. A 15-year mortgage (often at a lower rate, e.g. 5.9%) costs ~$3,357/month — $829 more — but only ~$204,237 in total interest, saving roughly $306,000. The 15-year builds equity twice as fast and costs far less overall, but requires committing to a higher monthly payment. Use the amortization schedule to compare both scenarios side by side.
The standard formula is: M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]. Where M = monthly payment, P = principal, r = monthly interest rate (annual rate ÷ 12), n = total payments (years × 12). Example: $400,000 at 6.5% for 30 years → r = 0.065/12 = 0.005417, n = 360 → M = $2,528/month. The calculator applies this formula to every payment row to build the full schedule.
Yes — significantly. Paying half your monthly amount every two weeks produces 26 half-payments (13 full payments) per year instead of 12. That one extra annual payment reduces principal faster and compounds savings. On a 30-year $400,000 mortgage at 6.5%, biweekly payments save approximately $76,000 in interest and pay off the loan about 5 years early — with no change to your monthly budget, just the payment frequency.
In most cases, yes. Standard conventional, FHA, and VA mortgages do not carry prepayment penalties. Under US federal law, prepayment penalties on residential mortgages are limited to the first three years of the loan and are prohibited entirely on FHA, VA, and USDA loans. Check your Closing Disclosure or ask your lender to confirm. Note: making extra payments does not lower your required monthly payment — it shortens your loan term and reduces total interest instead.