Math & Science · 15+ calculators

Math & Science Calculators

Free scientific, statistical, and everyday math tools with clear steps

From percentages and fractions to standard deviation and molecular weight, our math calculators use high-precision arithmetic and explain the formula behind every result.

Quick Answer · Featured snippet

Quick reference: 20% of 150 = 30; 15% tip on $84 = $12.60; 1 mile = 1.609 km; 1 gallon = 3.785 L; Rule of 72: money doubles in 72/rate years (7% = ~10 years).

Verified formulas, no signup · Updated for 2026

What makes our math & science calculators different

Updated for 2026

High-Precision Arithmetic

Internal math uses extended precision - rounding only happens for display, so the answers stay exact.

Formulas & Steps

Each calculator shows the formula and the working - useful for homework and self-checking.

Wide Topic Coverage

Arithmetic, percentages, fractions, geometry, statistics, unit conversion, and chemistry basics.

100% Free, No Signup

Every math tool is free to use - desktop, tablet, and mobile browsers supported.

Frequently asked questions about our math calculators

What math topics are covered?

Basic arithmetic, percentages, fractions, geometry (triangles, area, square footage), statistics (mean, standard deviation), chemistry (molecular weight), and more.

Are the results accurate?

Yes. We use high-precision internal math and only round for display. For pure-arithmetic calculators the result is exact up to the displayed precision.

Can I use these calculators for school?

Yes. Many students use our fraction, percentage, and percentage-change calculators to check homework. For learning, pair the answer with the formula shown on the page.

What is the standard deviation calculator for?

It measures the spread of a data set - used in statistics classes, research, quality control, and finance for risk/volatility.

Do I need to install anything?

No. All math calculators run in your browser - desktop, tablet, and phone.

Most Popular Math Calculators (2026)

The 12 math calculators that cover the most common everyday calculations. Click any link to use the tool with worked examples.

Percentage Calculator

20% of 50 = 10. 50 is what % of 200 = 25%. X increase from 80 to 100 = 25%.

Percent Off Calculator

25% off $80 = $60. Stacked 30%+20% = $56 (44% off).

Fraction Calculator

3/4 + 1/6 = 11/12. Add, subtract, multiply, divide, simplify.

Percentage Change Calculator

80 → 100 = +25%. 100 → 80 = −20%. Inflation 2→7% = +5pp (250%).

Scientific Calculator

sin(π/4) = 0.7071. log₁₀(1000) = 3. √(2² + 3²) = 3.606. Degrees/radians.

Exponent Calculator

2^10 = 1,024. 5^6 = 15,625. 16^(1/2) = 4. Negative + fractional.

Ratio Calculator

16:9 → 1.78:1. Simplify 24:36 = 2:3. Scale 1:50 → 2 cm = 1 m.

Percentage Increase Calculator

$50 → $60 = +20%. $60 → $50 = −16.67% (asymmetric).

GPA Calculator

3×A + 2×B = 3.4 GPA. Weighted (4.0/4.3/5.0) + unweighted scales.

Average Calculator

Mean of 10, 20, 30 = 20. Weighted avg (3×80 + 1×90) = 82.5.

Triangle Calculator

Right triangle 3-4-5: hypotenuse = 5, area = 6. Pythagorean theorem.

Random Number Generator

Random 1–100 = e.g. 47. Integer or decimal, no repeats, batch mode.

Sponsored

15+ Free Math Calculators — Scientific, Percentage & Fraction Tools | CalcCentral