76+ Free Calculators & Converters

Free Online Calculators & Unit Converters

Calculate BMI, EMI, tips, percentages, and convert length, weight, temperature, and more — free, fast, and accurate. Every tool shows its formula. No signup required.

Smart Calculator

Standard & Scientific with instant history log

Calculation History

No recent calculations

Universal Unit Converter

Real-time conversions across multiple metrics

Value to Convert

From

1.00

Meters

Financial & Tip Suite

Calculate tips, split bills, and estimate loan interest

Bill Amount ($)

Tip (%)

Split (People)

Tip Amount

$15.00

Per Person

$57.50

Geometry Solver

Shapes, areas, and Pythagorean calculations

Radius (r)

Area

78.54

Circumference

31.42

Online calculators for everyday math, health, and finance

CalculatorCamp is a free collection of online calculators and unit converters for work, school, and daily life. Start with the length conversion calculator, cm to feet converter, seconds to HH:MM:SS converter, kg to stone converter, kg to lbs, feet to cm, or basic calculator online — plus BMI, EMI, tip, percentage, and dozens more tools.

Every calculator is free, mobile-friendly, and shows the formula behind the result so you can trust the math. Browse popular tools below, open a category, or search for the exact converter you need.

Popular free calculators & converters

Basic Calculator Online Free online calculator for add, subtract, multiply, and divide. Essential Length Conversion Calculator Convert mm, cm, m, km, inches, feet, yards, and miles. Popular Kg to Lbs Converter Convert kilograms to pounds for body weight and gym plates. Popular Feet to Cm Converter Convert feet and inches to centimeters instantly. Popular Cm to Feet Converter Convert centimeters to feet and inches for height charts. Popular Seconds to HH:MM:SS Convert total seconds into hours, minutes, and seconds. Popular Kg to Stone Converter Convert kilograms to stone and pounds (UK body weight). Popular Meters to Feet Converter Convert meters to feet and inches instantly. Popular Gallons to Liters Convert US gallons to liters for fuel and liquids. Popular Scientific Calculator Trigonometry, logarithms, exponentials, and powers. Advanced Currency / Salary Exchange Convert hourly, daily, monthly, and yearly pay rates. Finance Mortgage Calculator Estimate monthly loan payments and interest total. Finance Tip & Bill Splitter Split restaurant bills and calculate gratuity easily. Daily BMI & Health Metrics Body Mass Index and daily caloric intake estimator. Health Geometry & Shapes Areas, circumferences, and Pythagorean theorem. Math Sales Discount Tool Calculate markdown savings and final checkout prices. Shopping Time & Date Diff Calculate days between timestamps or dates. Utility GPA & Grade Tool Estimate semester GPA and target grade benchmarks. Education Roadtrip Fuel Cost Plan gas consumption and mileage costs for trips. Travel

Browse all 76 tools →

Guides: how calculators & conversions work

All guides →

Health 3 min read BMI vs. body-fat percentage: why a “healthy” BMI can still be unhealthy BMI is a screening ratio of weight to height; body-fat percentage measures composition. Here is where they agree, where they disagree, and how to use both. Health 4 min read How much protein do you really need? What the research says, in grams 0.8 g/kg prevents deficiency; 1.6–2.2 g/kg builds and keeps muscle. Here is how to pick your number and split it across the day. Finance 4 min read EMI explained with an amortisation table: why early payments are mostly interest A full amortisation walk-through of a 1,000,000 loan at 12% — with the month-by-month table and a tenure comparison that shows where the interest really goes.

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