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.
Sleep Calculator
Find optimal bedtimes and wake times based on 90-minute sleep cycles.
Fraction Calculator
Add, subtract, multiply and divide fractions with automatic simplification.
GCF & LCM Calculator
Find the Greatest Common Factor and Least Common Multiple for any set of numbers...
Statistics Calculator
Calculate mean, median, mode, variance, standard deviation and more from a data...
Quadratic Equation Solver
Solve ax² + bx + c = 0 and get real or complex roots with step-by-step working.
Factorial Calculator
Calculate factorial (n!), permutations (nPr) and combinations (nCr) instantly.
Average Calculator
Calculate arithmetic, geometric and harmonic mean, plus weighted averages.
Prime Number Checker
Check if a number is prime and find its prime factorisation. List all primes in...
Percentage Difference Calculator
Calculate percentage difference, percentage change and percentage error between...
Business Days Calculator
Count working days between two dates or add business days to a start date.
Work Hours Calculator
Calculate total work hours, overtime and pay across a working week.
Age in Days Calculator
Find your exact age in days, hours and minutes — and countdown to your next birt...
Days Until Calculator
Live countdown to any future date in days, hours, minutes and seconds.
Time Duration Calculator
Add or subtract multiple time durations and convert between time formats.
Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin and Rankine instantly.
Length Converter
Convert between metres, feet, inches, kilometres, miles and more length units.
Weight Converter
Convert between kilograms, pounds, ounces, grams, stone and more weight units.
Area Converter
Convert between square metres, acres, hectares, square feet and more area units.