Free online tools for everyday calculations, planning, and quick web tasks

Calculate percent-of values, percent change, percent difference, and reverse percentages with visible formulas for discounts, markups, before-and-after values, and original-price reconstruction.

Calculate exact age in years, months, and days, total days lived, next birthday, weekday born, generation, zodiac sign, and age milestones.

Count words, characters, paragraphs, reading time, A4 pages, and standard pages from pasted text or local PDF, Word, OpenDocument, spreadsheet, presentation, ebook, subtitle, and text files.

Generate custom QR codes for URLs, Wi-Fi, contacts, email, SMS, phone numbers, locations, and events with SVG, PNG, payload, and iframe export.

Create a shareable Scrum poker room with live voting, reveal controls, configurable decks, and member moderation.

Generate color palettes from one seed color with harmony modes, accessible text colors, shade ramps, CSS variables, Tailwind colors, and JSON exports.

Calculate adult BMI, child and teen BMI percentiles, healthy weight range, BMI prime, and waist-to-height ratio with metric or US units.

Build and patch a modular synthesizer rack directly in the browser.

Calculate Satisfactory production chains with machines, rates, power, extraction, alternates, and amplification.

Find Stardew Valley loved gifts, liked backups, birthdays, seasonal availability, and heart goal estimates.

Convert GLB, GLTF, OBJ, and STL files into Minecraft block coordinates.

A keyboard-friendly scratch calculator for quick totals, percentages, ratios, per-unit costs, and order-of-operations checks while you work in the browser.

Calculate percent-of values, percent change, percent difference, and reverse percentages with visible formulas for discounts, markups, before-and-after values, and original-price reconstruction.

Calculate the percent increase from a start value to a final value, with the increase amount shown as the bridge between the two numbers.

Compare two measurements with symmetric percent difference, using the absolute gap divided by the average magnitude so neither value is treated as the original.

Calculate the final value after a percentage decrease by separating the original baseline, the amount removed, and the remaining value.

Back out the original value when you know the final value and the percentage increase or decrease that produced it.

Calculate the true sale price from a list price by applying the markdown first, then adding tax only to the discounted subtotal.

Compare a measured value with an accepted reference value by making absolute error visible first, then converting that error into a relative percentage.

Add, subtract, multiply, and divide fractions exactly, without decimal rounding, then read the simplified final result.

Simplify fractions into lowest terms by finding the GCD of the numerator and denominator, preserving the equivalent value, and normalizing signs.

Convert mixed numbers into improper fractions for exact arithmetic, then reduce and return the answer as a simplified fraction or mixed number.

Convert a decimal into the cleanest reduced fraction that fits a chosen denominator limit, showing when the result is exact and when it is an approximation.

Calculate exact age in years, months, and days, total days lived, next birthday, weekday born, generation, zodiac sign, and age milestones.

Count calendar days, business days, weekends, full weeks, approximate months, direction, and monthly breakdown between two dates.

Add or subtract years, months, weeks, days, and business days from a date with month-end rules and repeat previews.

Convert a date and time between IANA time zones with UTC, GMT offsets, weekday changes, and a comparison table.

Track live times across world time zones with offsets, dates, weekday changes, and work-hours status.

Convert Unix timestamps in seconds, milliseconds, microseconds, or nanoseconds to dates, UTC, ISO 8601, and back again.

Count business days between dates or add and subtract workdays with configurable weekends and holiday exclusions.

Generate custom QR codes for URLs, Wi-Fi, contacts, email, SMS, phone numbers, locations, and events with SVG, PNG, payload, and iframe export.

Count words, characters, paragraphs, reading time, A4 pages, and standard pages from pasted text or local PDF, Word, OpenDocument, spreadsheet, presentation, ebook, subtitle, and text files.

Create a shareable Scrum poker room with live voting, reveal controls, configurable decks, and member moderation.

Generate color palettes from one seed color with harmony modes, accessible text colors, shade ramps, CSS variables, Tailwind colors, and JSON exports.

Check WCAG contrast ratios for foreground and background colors, preview real text, see AA and AAA pass results, and copy an accessibility report.

Upload an image, click to sample any pixel color, extract a dominant palette, and copy HEX, RGB, HSL, CSS variables, or JSON.

Calculate adult BMI, child and teen BMI percentiles, healthy weight range, BMI prime, and waist-to-height ratio with metric or US units.

Convert GLB, GLTF, OBJ, and STL files into Minecraft block coordinates.

Convert images into Minecraft block pixel art with palette controls, previews, and exports.

Convert images into Minecraft map art with map size controls, map previews, palettes, and exports.

Calculate Satisfactory production chains with machines, rates, power, extraction, alternates, and amplification.

Estimate Stardew Valley crop profit, harvest days, seed cost, and best crops for a season window.

Track Stardew Valley Community Center bundles by room, season, item source, reward, and completion progress.

Find Stardew Valley loved gifts, liked backups, birthdays, seasonal availability, and heart goal estimates.

Generate Minecraft circles, spheres, domes, pyramids, cones, cylinders, ellipsoids, and torus blueprints with layers, block counts, and 3D previews.

Create pixel circle charts, outlines, filled disks, and row-by-row Minecraft circle templates.

Generate hollow or filled Minecraft sphere layers with a 3D block preview.

Generate Minecraft dome and hemisphere roof layers with block counts and a 3D preview.

Generate Minecraft pyramid layers for temples, roofs, monuments, and survival builds.