Free Calculators

Free compound interest, BMI, GPA, and trip fuel cost calculators. No sign-up — everything runs in your browser.

Compound Interest Calculator

See how savings grow with monthly deposits and compound interest over time. MoneyFree · No sign-up

BMI Calculator

Body mass index in metric or US units, with the standard adult ranges. HealthFree · No sign-up

GPA Calculator

Add your courses, credits, and grades to get your GPA on a 4.0 scale. EducationFree · No sign-up

Trip Fuel Cost Calculator

What a road trip will cost in fuel — and what each person pays. TravelFree · No sign-up

Why these tools are free

Brass Smile is supported by advertising and clearly labeled affiliate links. The tools run entirely in your browser, so we never see what you enter — not even the numbers you enter.