Math & Conversion Calculator Hub
Free math tools for students, professionals, and everyday calculations. Percentages, fractions, area, volume, unit conversions, and more.
Percentage Calculator
Calculate percentages, percentage change, increase/decrease, and more. The most versatile percentage tool you'll find.
Calculate Percentage →Unit Converter
Convert between hundreds of units: length, weight, temperature, speed, data, and more. Instant and accurate.
Convert Units →Fraction Calculator
Add, subtract, multiply, and divide fractions. Simplify fractions and convert between fractions, decimals, and percentages.
Calculate Fractions →GPA Calculator
Calculate your grade point average for a semester or cumulative GPA. Supports weighted and unweighted scales.
Calculate GPA →Area Calculator
Calculate the area of any shape: rectangle, circle, triangle, trapezoid, ellipse, and more. With visual diagrams.
Calculate Area →Volume Calculator
Find the volume of 3D shapes: cube, sphere, cylinder, cone, pyramid, and more. Perfect for math and real-world projects.
Calculate Volume →Random Number Generator
Generate random numbers within any range. Great for games, drawings, sampling, and decision-making.
Generate Number →Scientific Calculator
Full-featured scientific calculator with trigonometry, logarithms, exponents, roots, and memory functions.
Open Calculator →Essential Math Reference
Quick reference for commonly needed formulas and conversions.
Percentage Formula
Percentage = (Part / Whole) x 100. To find X% of Y: multiply Y by X/100. Percentage change: ((New - Old) / Old) x 100.
Area Formulas
Rectangle: L x W. Triangle: (B x H) / 2. Circle: pi x r². Trapezoid: ((a + b) / 2) x h.
Volume Formulas
Cube: s³. Rectangular prism: L x W x H. Cylinder: pi x r² x h. Sphere: (4/3) x pi x r³.
Unit Conversion Basics
1 mile = 1.609 km. 1 kg = 2.205 lbs. 1 gallon = 3.785 liters. Fahrenheit to Celsius: (F - 32) x 5/9.
Quick Reference Charts
Fraction-Decimal-Percent
- 1/8 = 0.125 = 12.5%
- 1/4 = 0.25 = 25%
- 1/3 = 0.333 = 33.3%
- 1/2 = 0.5 = 50%
- 2/3 = 0.667 = 66.7%
- 3/4 = 0.75 = 75%
Powers of 2
- 2¹ = 2
- 2² = 4
- 2³ = 8
- 2⁴ = 16
- 2⁵ = 32
- 2¹⁰ = 1,024
GPA Scale
- A (93-100): 4.0
- A- (90-92): 3.7
- B+ (87-89): 3.3
- B (83-86): 3.0
- B- (80-82): 2.7
- C+ (77-79): 2.3
Metric Prefixes
- Kilo (k): 1,000
- Mega (M): 1,000,000
- Giga (G): 1,000,000,000
- Milli (m): 0.001
- Micro (u): 0.000001
- Nano (n): 0.000000001
Need a Quick Calculation?
Start with our percentage calculator — the most popular math tool on CalcDrop.