Browse all 251 free calculators on CalculatorOK. Every tool runs in your browser, needs no sign up, and shows the result instantly. Pick a category below or use the search box in the menu.
Finance & Money
- APY Calculator
- Break-Even Calculator
- CAGR Calculator
- Car Depreciation Calculator
- CD Calculator
- Commission Calculator
- Compound Interest Calculator
- Discount Calculator
- Discounted Cash Flow Calculator
- Future Value Calculator
- Hourly to Salary Calculator
- IRR Calculator
- Least Common Multiple (LCM) Calculator
- Loan Calculator
- Margin Calculator
- Margin Calculator
- Markup Calculator
- NPV Calculator
- Present Value Calculator
- Rent Calculator
- Return on Assets Calculator
- Return on Equity Calculator
- Return on Invested Capital Calculator
- Return on Sales Calculator
- ROI Calculator
- Salary to Hourly Calculator
- Time Value of Money Calculator
- Tip Calculator
- Value of College Degree Calculator
- VAT Calculator
- VAT Calculator
- WACC Calculator
- XIRR Calculator
Business
Education
Health & Fitness
- Army Body Fat Calculator
- BMI Calculator
- BMR Calculator
- Body Fat Calculator
- Body Surface Area Calculator
- Calorie Calculator
- Carbs Calculator
- Daily Water Intake Calculator
- Dog Years Calculator
- Estimated Energy Requirement Calculator
- Fat Intake Calculator
- Healthy Weight Calculator
- Height Calculator
- Height Comparison
- Ideal Weight Calculator
- Keto Calculator
- Lean Body Mass Calculator 💪
- Macronutrient Calculator
- Pace Calculator
- Protein Calculator
- Protein Requirement Calculator
- Resting Metabolic Rate Calculator
- Sobriety Calculator
- Target Heart Rate Calculator
- TDEE Calculator
- Thermic Effect of Food Calculator
- Weight Loss Calculator
- Weighted Average Calculator
Date & Time
- Add Days Calculator
- Age Calculator
- Age Difference Calculator
- Anniversary Calculator
- Birthday Calculator
- Birthday Countdown Calculator: Make Every Celebration Unforgettable
- Business Days Calculator
- Calendar Calculator
- Chronological Age Calculator
- Countdown Timer to Any Date and Time
- Date & Time Duration Calculator
- Day Counter
- Day of the Week Calculator
- Days Calculator
- Days Until Date Calculator – Find How Many Days Until …?
- End of School Countdown Calculator
- Hours Calculator
- How Many Days Until Christmas 2026?
- How Many Days Until Easter 2026?
- How Many Weeks Are Left in the Year? – Weeks Left in 2026
- Leap Year Calculator
- Month Calculator & Counter
- Start of School Countdown Calculator
- Start of School Countdown Calculator
- Time Calculator
- Time Card Calculator
- Wedding Countdown Calculator – Track Your Big Day Easily
Mathematics
- Antilog Calculator
- Arithmetic Mean Calculator
- Binary Calculator / Converter
- Decimal to Fraction Calculator
- Decimal to Percent Calculator
- Exponent Calculator
- Fraction Calculator
- Fraction to Decimal Calculator
- Fraction to Percent Calculator
- Geometric Mean Calculator
- Greatest Common Divisor (GCD) Calculator
- Harmonic Mean Calculator
- Hex Calculator / Converter
- Least Common Denominator (LCD) Calculator
- Logarithm Calculator
- Mean, Median & Mode Calculator
- Mode Calculator
- Percent Error Calculator
- Percent Off Calculator
- Percent to Decimal Calculator
- Percent to Fraction Calculator
- Percentage Calculator ％
- Percentage Decrease Calculator
- Percentage Increase Calculator
- Proportion Calculator
- Ratio Calculator
- Root Calculator
- Scientific Notation Calculator / Converter
- Sequence Calculator
- Sequence Calculator
- Significant Figures Calculator
- Simplify Fractions Calculator
- Standard Form Calculator
- Summation Calculator
Geometry
- Aquarium Volume Calculator
- Area Calculator
- Area of a Circle Calculator
- Area of a Parallelogram Calculator
- Area of a Rectangle Calculator
- Area of a Sector Calculator
- Area of a Square Calculator
- Area of a Triangle Calculator
- Area of Octagon Calculator
- Circumference of a Circle Calculator
- Cube Root Calculator
- Endpoint Calculator
- Hexagon Calculator ⬢
- Midpoint Calculator
- Perimeter Calculator
- Perimeter of a Rectangle Calculator
- Perimeter of a Square Calculator
- Perimeter of a Triangle Calculator
- Square Root Calculator
- Surface Area Calculator
- Volume Calculator
- Volume of a Box Calculator
- Volume of a Cone Calculator
- Volume of a Cube Calculator
- Volume of a Cylinder Calculator
- Volume of a Prism Calculator
- Volume of a Sphere Calculator
Trigonometry
- Arccos Calculator
- Arccot Calculator
- Arcsine Calculator
- Arctan Calculator
- Cosine Calculator
- Cotangent Calculator
- Sine Calculator
- Tangent Calculator
- Trigonometry Calculator
Statistics
- Bayes Theorem Calculator
- Binomial Distribution Calculator
- Binomial Distribution Calculator
- Chi-Square Calculator
- Chi-Square to P-value Calculator
- Coefficient of Variation Calculator
- Combination Calculator
- Confidence Interval Calculator
- Correlation Coefficient Calculator
- Covariance Calculator
- Critical Value Calculator
- Error Function Calculator
- Hazard Ratio Calculator
- Normal Distribution Calculator
- Normality Calculator
- Odds Calculator
- Odds Ratio Calculator
- Permutations Calculator
- Power & Sample Size Calculator
- P-value Calculator
- P-value to Z-score Calculator
- Relative Risk Calculator
- Sample Ratio Mismatch Calculator
- Severity Calculator
- Sigma Level Calculator
- Standard Deviation Calculator
- Z Score Calculator
- Z-score to P-value Calculator
Physics
- Acceleration Calculator
- Angular Velocity Calculator
- Buoyancy Calculator
- Capacitor Energy & Charge Calculator ⚡
- Density Calculator
- Flow Rate Calculator
- Half-Life Calculator
- Ideal Gas Law Calculator
- Impact Force Calculator
- Kinetic Energy Calculator
- Ohm’s Law Calculator ⚡
- Reynolds Number Calculator
- Terminal Velocity Calculator
- Thermal Expansion Calculator
- Van der Waals Calculator
Construction & Home
- Asphalt Calculator
- Brick Calculator
- Concrete Calculator
- Concrete Calculator
- Gravel Calculator
- Height Percentile Calculator
- IQ Percentile Calculator
- Metal Weight Calculator
- Mulch Calculator
- Paint Calculator
- Pool Volume Calculator
- Sand Calculator
- Square Footage Calculator
- Tank Volume Calculator
- Tile Calculator
- Topsoil Calculator
Cooking
- Bread Calculator
- Brine Calculator
- Coffee Ratio Calculator ☕
- Pizza Dough Calculator
- Recipe Scaler
- Rice Calculator
- Rice to Water Ratio Calculator
- Salt Brine Calculator
Transportation
- Average Speed Calculator
- Container Loading Calculator
- Fuel Calculator ⛽
- Gas Mileage (MPG) Calculator
- Pallet Calculator
- Speed, Distance & Time Calculator
Randomizers
- Dice Probability Calculator
- Lucky Number Generator 🍀
- Random Number Generator 🎲
- Random Password Generator
Security & Data
- Body Shape Calculator
- Download Time Calculator
- MD5 Generator
- RAID Calculator
- SHA1 Generator
- SHA-256 Generator
- SHA-512 Generator