8 free calculators for everyday math — percentage, loan, BMI, age, date difference, tip, discount, and scientific. All browser-based, no signup.
% of, X is what % of Y, % change
Monthly payment, total interest, amortization
Metric & imperial, category gauge
Exact age in years, months, days
Days, weeks, months, business days
Tip amount + bill split
Sale price, savings, % off
Trig, log, powers, DEG/RAD