Free Online Calculator Tools
Free Online Calculators for
Math, Science & Engineering
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CalculatorPort offers 200+ free online calculators covering math, physics, chemistry, unit conversions, and finance. Fast, accurate, works on any device. No account required.
200+Free Tools
19Categories
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Scientific Calculator
Most Used
Popular Calculators
Our most-used tools — quick access to the calculators people reach for every day.
Age Calculator
Your exact age in years, months & days.
Compound Interest
Calculate investment growth over time.
Ohm's Law Calculator
Find voltage, current or resistance (V=IR).
Temperature Converter
Celsius, Fahrenheit, Kelvin & Rankine.
nCr Calculator
Combinations — choose r from n objects.
Area Calculator
Area & perimeter for all geometric shapes.
Infix → Postfix
Convert expressions to Reverse Polish Notation.
Weight Converter
kg, lbs, oz, grams & more conversions.
All Subjects
Browse by Category
Choose your subject. Every category has multiple free tools with formulas and examples.
Math Calculators
LCM, HCF, factorials, averages, nCr/nPr, compound & simple interest
Physics
Ohm's Law, gravity, centripetal acceleration, displacement & 15+ more
Chemistry
Molar mass, ideal gas law, solution concentration, molecular weight
Unit Converters
Length, weight, temperature, volume, pressure, speed, power & energy
Bitwise
AND, OR, XOR, NOR, bit shifts — built for CS students & developers
Area & Perimeter
Circles, rectangles, triangles, squares with step-by-step formulas
Data Structures
Infix, postfix & prefix expression converters for CS coursework
Finance
Compound interest, simple interest & investment growth calculators
Can’t find what you need? Use the search bar to find any calculator instantly.
Why Students & Professionals Choose CalculatorPort
Simple tools. Accurate results. No barriers.
Instant Results
Every calculator delivers answers immediately — no waiting, no loading.
Step-by-Step Working
We show the formula and every calculation step, not just the final number.
Works on Any Device
Fully mobile-responsive. Use on desktop, tablet, or smartphone — always free.
Learn & Calculate
From the Blog
Guides and tutorials that explain the math behind the tools.