Calculator
Free online calculators for everyday and work needs including date calculator, percentage calculator, and ratio calculator.
Tools
44 toolsDays Remaining This Year
Calculate how many days remain until the end of the year in real-time. Track your...
Age Calculator
Calculate your exact age in years, months, and days. Discover your zodiac sign, Chinese zodiac,...
Date Difference Calculator
Calculate duration between two dates in years, months, weeks, and days with weekday/weekend breakdown.
Date Countdown Calculator
Calculate D-Day until your target date with real-time countdown and auto-save.
Percent Calculator
Calculate various percentages easily. Includes basic percent, ratio, change rate, discount, and reverse calculation with...
Days Lived Calculator
Calculate how many days you've lived since birth. Real-time counter showing hours, minutes, seconds. View...
Birthday Weekday Calculator
Enter any date to instantly discover which day of the week it falls on. Includes...
Proportion Calculator
Free proportion calculator for solving proportions, rule of three, proportional distribution, inverse proportion, and chain...
Biorhythm Calculator
Enter your birth date to visualize your physical, emotional, and intellectual biorhythm cycles. Track daily...
PSI to GPM Calculator
Enter pressure (PSI) and a US K-factor to estimate flow in GPM, L/min, and L/s,...
FPE Calculator
Calculate foot-pounds of energy (FPE) from grain weight and fps. Instantly view Joules, m/s conversion,...
Pay Raise Calculator
Check new salary, raise amount, monthly change, target gap, and future projection in USD from...
Density Calculator
Enter any two of mass, volume, and density to solve the third value, then compare...
Molecular Weight Calculator
Calculate molecular weight (molar mass) from a chemical formula with element contribution, total atoms, hydrate...
Molarity Calculator
Calculate moles, molarity (M), mM, and required mass for standard volumes from solute mass, molar...
Horsepower Calculator
Enter torque and RPM to calculate hp, PS, and kW together, with normalized N·m torque...
Percent Error Calculator
Enter a reference value and a measured value to review percent error, absolute error, signed...
Right Triangle Calculator
Calculate the base, height, hypotenuse, acute angles, area, perimeter, and trig ratios of a right...
Z-Score Calculator
Calculate Z-score, cumulative percentile, distance from the mean, and reference score bands from a score,...
Discount Calculator
Calculate the final paid amount, total savings, and original subtotal from list price, discount rate,...
Roofing Calculator
A roofing calculator tuned for square-foot and bundle-based estimates, with pitch, waste allowance, roofing squares,...
Standard Deviation Calculator
Paste a list of numbers to calculate the sample standard deviation, population standard deviation, variance,...
Circle Calculator
Solve the rest of a circle from radius, diameter, circumference, or area, then review the...
Voltage Drop Calculator
Calculate voltage drop, receiving voltage, and wire loss for single-phase, three-phase, and DC circuits, then...
Root Calculator
Calculate square roots, cube roots, and other nth roots with powered verification, perfect-power checks, and...
Slope Calculator
Enter two coordinates to calculate the slope, line equation, slope angle, midpoint, distance, rise, and...
Pythagorean Theorem Calculator
Enter any two known sides of a right triangle to solve the missing side, verify...
Surface Area Calculator
Enter dimensions for a cube, rectangular prism, cylinder, sphere, or cone to calculate total surface...
Average Calculator
Paste numbers to calculate the arithmetic mean, median, sum, minimum, maximum, and range. Useful for...
Gravel Calculator
Enter area, depth, density, and extra allowance to estimate gravel order volume, weight, bag count,...
Fraction Calculator
Free online fraction calculator for two fractions with simplified answers, mixed numbers, decimal approximations, and...
p-value Calculator
A calculator that uses a Z or t statistic, test direction, degrees of freedom, and...
Factorial Calculator
Calculate exact factorials from 0! to 5,000! and review the digit count, trailing zeros, expansion,...
Camera Exposure Value (EV) Calculator
Enter any two values among aperture, shutter speed, and EV to calculate the third at...
Weighted Average Calculator
Enter values and weights row by row to see the weighted average, weighted sum, simple-average...
Fixed ISO Exposure Calculator
Use a fixed ISO and a reference aperture/shutter pair to calculate the matching shutter or...
Factor Calculator
Enter a positive integer to view the prime factorization, full factor list, factor count and...
Confidence Interval Calculator
Review t-based mean and Wilson proportion confidence intervals from a sample mean or proportion, with...
Rounding Calculator
Round numbers by decimal places, nearest units, or significant figures and review the difference from...
Goal Achievement Rate Calculator
Enter a goal value and current progress to review the current achievement rate, remaining amount,...
Coefficient of Variation (CV) Calculator
Enter a number list or a mean and standard deviation to calculate sample or population...
Hydrogen Peroxide Concentration Calculator
Work out hydrogen peroxide stock volume, water amount, and dilution factor from the stock concentration,...
Percentage Change Calculator
See percentage change, raw difference, a base-100 index, and the rate needed to recover the...
Start and End Time Calculator
Calculate end times, reverse-calculate start times, and review break-adjusted work hours and overnight schedules on...