Calculate Anything.Understand Everything.

366+ free calculators with step-by-step explanations and formulas.

Popular Calculators

Mortgage Calculator

Estimate monthly mortgage payments with taxes, insurance, and PMI.

Loan Calculator

Calculate monthly payments, total interest, and amortization for any loan.

Compound Interest Calculator

See how your money grows with compound interest over time.

Percentage Calculator

Find percentages, increases, and differences between values.

BMI Calculator

Calculate your Body Mass Index and see your health classification.

Calorie Calculator

Find your daily caloric needs for weight loss, maintenance, or gain.

Age Calculator

Calculate exact age in years, months, and days from any date.

Scientific Calculator

Evaluate scientific functions: trig, log, exp, factorial.

GPA Calculator

Calculate your cumulative or semester GPA on a 4.0 scale.

Tip Calculator

Calculate tips and split bills between groups.

Date Calculator

Calculate days between dates or add days to a date.

Discount Calculator

Calculate sale prices, savings, and discount percentages.

Standard Deviation Calculator

Find the standard deviation and variance of a data set.

Salary Calculator

Convert salary between hourly, weekly, biweekly, monthly, and annual amounts.

Conversion Calculator

Convert between common units of length, weight, and temperature.

Root Calculator

Calculate square roots, cube roots, or any nth root of a number.

All Categories

Financial Calculators

87 calculators

Health Calculators

38 calculators

Math Calculators

51 calculators

Conversion Calculators

53 calculators

Date & Time Calculators

23 calculators

Statistics Calculators

23 calculators

Engineering Calculators

32 calculators

Everyday Calculators

26 calculators

Construction Calculators

22 calculators

Education Calculators

11 calculators

The Smarter Way to Calculate

CALTRX is a free online calculator platform built for clarity. Every tool includes step-by-step explanations that show exactly how your result was calculated, turning a simple answer into genuine understanding.

Whether you need a mortgage calculator to plan a home purchase, a BMI calculator for a health check, or a percentage calculator for quick math, every tool is designed to be fast, accurate, and educational.

From financial planning and health metrics to engineering formulas and statistical analysis, CALTRX covers 366+ calculators across 10 categories — all free, with no account required.