PDFAITools
Tool Guides & How-Tos
Step-by-step guides for every tool — learn what it does, how to use it, tips, and FAQ. 441 guides available.
Confidence Interval Calculator
Calculate confidence intervals for means and proportions at 90%, 95% or 99% conf...
Matrix Calculator
Add, subtract, multiply matrices and find determinant, inverse and transpose for...
Slope Calculator
Calculate slope, y-intercept, line equation, distance and midpoint between two p...
Logarithm Calculator
Calculate log base 10, natural log, log base 2 or any custom base. Includes anti...
Ratio Calculator
Simplify ratios, solve proportions and scale ratios up or down.
Rounding Calculator
Round numbers using half-up, half-even, ceiling, floor or truncation — all metho...
Scientific Notation Calculator
Convert numbers to and from scientific notation and perform multiplication/divis...
Sample Size Calculator
Calculate the required sample size for any population at your desired confidence...
Percent Error Calculator
Calculate percent error, absolute error and relative error between experimental...
Exponent Calculator
Calculate powers and roots for any base and exponent including decimals and nega...
Half-Life Calculator
Calculate radioactive decay, remaining quantity and half-lives elapsed. Includes...
Distance Calculator
Calculate distance between two coordinate points in 2D or 3D using Euclidean and...
P-Value Calculator
Calculate p-value for Z, T, Chi-square and F test statistics with one-tail and t...
Day of the Week Calculator
Find the day of the week for any date. Shows ISO week number, day of year and qu...
GPA Calculator
Calculate semester and cumulative GPA on a 4.0 or 5.0 scale with dynamic course...
Grade Calculator
Calculate your weighted grade average or find what score you need on your final...
Golf Handicap Calculator
Calculate your WHS golf handicap index from score differentials using the World...
Random Number Generator
Generate random numbers in any range, roll dice (d4–d100) or flip a coin.