Finance & Money

Loan Comparison

Compare two loan offers side-by-side to find total interest paid.

Even a 1% rate difference on a large loan can mean thousands of dollars in extra interest over the life of the loan. This tool makes that gap visible so you can make an informed borrowing decision.

Enter your numbers

Loan Amount ($)

Rate 1 (%)

Rate 2 (%)

Term (Years)

Results update as you change the inputs. Calculations run in your browser.

Difference in total interest

$908.72

option1 Monthly: $477.53
option2 Monthly: $492.67
option1 Interest: $3651.74
option2 Interest: $4560.46

See the formula

Formula and method

PMT = P × [r(1+r)^n] / [(1+r)^n - 1]; Total Interest = (PMT × n) - P

Standard amortizing loan math. Monthly payment is derived from the present value annuity formula. Total interest is simply total paid minus principal.

Worked examples

Car loan comparison

Loan Amount ($):: 35000
Rate 1 (%):: 4.9
Rate 2 (%):: 6.9
Term (Years):: 6

Difference in total interest: $2374.95

Personal loan

Loan Amount ($):: 15000
Rate 1 (%):: 8.5
Rate 2 (%):: 11.5
Term (Years):: 3

Difference in total interest: $760.57

Assumptions and limits

Monthly compounding and payments
Fixed rate for full term
No origination fees or prepayment penalties

This tool provides an educational estimate. Rules, rates and personal circumstances can change the answer. Review the assumptions before relying on a result. Report a correction.

Common mistakes to avoid

Comparing APR to a nominal rate — always compare the same type of rate.
Ignoring origination fees, which can make a lower-rate loan more expensive overall.
Using annual payments instead of monthly — most loans amortize monthly.

Frequently asked questions

Does this include fees?

No. Origination fees, broker fees, and other charges are not included. Always request the full APR (Annual Percentage Rate) from lenders, which includes these costs.

What if I plan to pay off the loan early?

Early payoff changes the math significantly. Use the total interest figure as a worst-case scenario. Every extra payment directly reduces principal and cuts future interest.