Free Online Calculators

Fast, accurate, and free — no signup required. Finance, health, math, and more.

Finance

Mortgage Calculator

Estimate your monthly mortgage payment with taxes and insurance.

Salary Calculator

Calculate your take-home pay after federal and state taxes.

Compound Interest Calculator

See how your savings and investments grow over time.

Health

Check your body mass index and healthy weight range.

TDEE / Calorie Calculator

Find your total daily energy expenditure and calorie needs.

Due Date Calculator

Calculate your estimated pregnancy due date and milestones.

Math & Utility

Percentage Calculator

Find percentages, percentage change, and percent of a number.

Calculate your exact age in years, months, days, and more.

Calculate gratuity and split the bill between multiple people.

Convert length, weight, temperature, volume, speed, and more.

Why mycalcstool?

100% free — no account, no fees
All calculations happen in your browser — your data never leaves your device
Updated for 2026 tax rates and rules
Mobile-friendly and fast