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
Top picks · Most-clicked this month
Most popular math calculators
Percentage Calculator
X% of Y, percent change, increase/decrease
Scientific Calculator
Trig, logs, exponents & memory keys
Fraction Calculator
Add, subtract, multiply, divide & simplify
Percentage Change
Increase or decrease between two values
Triangle Calculator
Sides, angles, area, perimeter in one tool
Random Number
Generate numbers in any range with no repeats
Looking for something specific? Try the search above or jump to the full list below.
See all 15+ calculatorsAll math & science calculators
15+ free tools · sorted by topic100% freeNo signup
Percentage Calculator
Percent, discount, tip, percentage change
Scientific Calculator
Trigonometric, logarithmic, exponential functions
Fraction Calculator
Add, subtract, multiply, divide, simplify
Percentage Change Calculator
Increase or decrease between two values
Percent Off Calculator
Sale price after discount with sales tax
Triangle Calculator
Sides, angles, area, perimeter
Square Footage Calculator
Area in sq ft and sq m for any shape
Random Number Generator
Generate numbers in a range
Decimal to Fraction Calculator
Convert decimals to fractions and vice versa
Proportion Calculator
Solve a/b = c/d for the missing value
Exponent Calculator
Calculate powers, roots, and scientific notation
Standard Deviation Calculator
Mean, variance, sample & population std dev
Concrete Calculator
Volume, cubic yards, and bag count
Parlay Calculator
Combine legs, odds and parlay payout
Molecular Weight Calculator
Molar mass from any chemical formula
What makes our math & science calculators different
Updated for 2026High-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.