Calculators and converters
Browse free calculators for math, shopping, cooking, time, home projects, energy, and travel.
21 of 21 calculators shown
Math
Percentages, percentage change, and quick everyday math.
Percentage calculator
Calculate percentage of a value, part-of-whole percentage, reverse percentages, add/subtract percentages, and percentage change with guided modes.
Percentage change calculator
Calculate percentage increase or decrease between a starting value and a new value, with direction and absolute difference.
Shopping
Tips, bill splitting, discounts, and simple purchase checks.
Units and Cooking
Common units, kitchen measures, and ingredient conversions.
Unit converter
Convert common length, area, weight, temperature, volume, speed, pressure, storage, energy, power, time, data rate, fuel economy, and angle units.
Cooking converter
Convert kitchen volumes, ingredient weights, cup standards, and recipe servings.
Cups to grams calculator
Convert cups to grams for common ingredients with US or metric cups, serving scaling, and density notes.
Grams to cups calculator
Convert grams to cups for common ingredients with US or metric cups, serving scaling, and density notes.
Time and Date
Durations, date gaps, ages, and schedule math.
Time duration calculator
Calculate elapsed time across dates and times, with break subtraction and rounding.
Date difference calculator
Calculate days, weeks, months, inclusive date counts, and weekday counts between two dates.
Age calculator
Calculate age in years, months, days, total days, weeks, months, and next birthday timing.
Home Projects
Room area, paint, tile, flooring, and wallpaper estimates.
Paint calculator
Estimate paint from room dimensions, openings, coats, coverage, waste, and container size.
Tile calculator
Estimate tile pieces, coverage, boxes, waste, and leftover tile from project area and tile size.
Room area calculator
Calculate room area for one or two rectangular sections, subtract cutouts, and estimate perimeter.
Flooring calculator
Estimate flooring area, waste, boxes, cost, and leftover coverage.
Wallpaper calculator
Estimate wallpaper rolls from room perimeter, wall height, openings, roll size, repeat, and waste.
Energy and Travel
Electricity cost, appliance running cost, fuel cost, and travel time.
Electricity cost calculator
Calculate electricity cost from watts, usage time, days, standby power, rate, and fixed fees.
Appliance running cost calculator
Estimate appliance running cost from wattage, duty cycle, daily runtime, standby power, days, and electricity rate.
Fuel cost calculator
Estimate fuel needed, fuel cost, round trip cost, shared cost, tolls, and parking.
Travel time calculator
Estimate travel time with distance, speed, stops, buffer, and optional departure time.