Everyday calculators
Percentages, rule of three, discounts and tips, unit conversion, dates and geometry - locally in your browser, no upload.
Discount Calculator
Work out locally the final price after a discount and how much you save - no upload, in your browser.
Tip Calculator
Work out locally the tip, total and share per person - no upload, right in your browser.
Percentage Calculator
Work out locally how much a percentage of a value is - plus increased and decreased, no upload.
Rule of Three Calculator
Solve the rule of three locally: from "A corresponds to B" you work out what belongs to C - plus value per unit, no upload.
Percentage Change
Work out locally the percentage change from an old to a new value - plus the difference and the factor, no upload.
Inverse Rule of Three
Solve the inverse rule of three locally: more of A means less result - more workers, less time. No upload.
Fuel Cost Calculator
Work out locally the fuel cost of a trip from distance, consumption and price - no upload, in your browser.
Energy Cost Calculator
Work out locally an appliance's electricity cost per day, month and year from power, usage and price.
Aspect Ratio
Work out the aspect ratio from width and height - reduced, as a decimal and with a proportional target height. Locally, no upload.
Pixel Density
Work out pixel density (PPI) from resolution and screen diagonal - with dot pitch and megapixels. Locally, no upload, in your browser.
Circle
Work out the area, perimeter and diameter of a circle from its radius or diameter. Locally, no upload, in your browser.
Rectangle
Work out the area, perimeter and diagonal of a rectangle from its length and width. Locally, no upload, in your browser.
Triangle
Work out the area, perimeter and largest angle of a triangle from its three side lengths. Locally, no upload.
Length converter
Convert lengths locally between metric and imperial units like metre, kilometre, mile, foot and inch. No upload, in your browser.
Weight converter
Convert weights locally between tonne, kilogram, gram, milligram, pound and ounce. No upload, in your browser.
Temperature
Convert temperatures locally between Celsius, Fahrenheit and Kelvin. No upload, in your browser.
Data size
Convert data sizes locally between byte, KB, MB, GB, TB and the binary units KiB, MiB, GiB. No upload, in your browser.
Unit Price Calculator
Compare two products locally by their unit price and instantly see which is cheaper and how much you save. No upload.
Date Difference
Work out the span between two dates locally: total days plus a breakdown into years, months and days. No upload.
Working Days
Count the working days between two dates locally: weekdays Monday to Friday minus public holidays. No upload.
Week Number
Find the ISO 8601 calendar week number for any date locally - with the ISO year, weekday and day of the year, no upload.