---
title: "Free browser tools — calculators, converters and generators"
description: "Calculators, text tools, generators and converters that run entirely in your browser. No sign-up, no uploads, and they work offline once loaded."
url: https://atoneplace.net/tools/
site: "At One Place"
---

# Tools

Small tools that do one thing. All of them run entirely in your browser — nothing is uploaded, there is no sign-up, and they keep working offline once the page has loaded.

## Calculators

- [Percentage calculator](https://atoneplace.net/tools/percentage-calculator/) — Work out a percentage of a number, what percent one number is of another, and percentage change.
- [Loan and EMI calculator](https://atoneplace.net/tools/loan-calculator/) — Monthly payment, total interest and total repaid for any loan amount, rate and term.
- [BMI calculator](https://atoneplace.net/tools/bmi-calculator/) — Body mass index from height and weight, in metric or imperial, with what the number does and does not mean.
- [Tip calculator](https://atoneplace.net/tools/tip-calculator/) — Work out a tip and split the bill, with the per-person figure rounded sensibly.
- [Age calculator](https://atoneplace.net/tools/age-calculator/) — Exact age in years, months and days from a date of birth, plus total days and the next birthday.
- [Paint calculator](https://atoneplace.net/tools/paint-calculator/) — How much paint a room needs, allowing for doors, windows and the number of coats.
- [Compound interest calculator](https://atoneplace.net/tools/compound-interest-calculator/) — Growth of a lump sum plus regular contributions, with the interest shown separately.
- [Calorie and BMR calculator](https://atoneplace.net/tools/calorie-calculator/) — Resting metabolic rate and daily calorie needs by activity level.
- [Dog age calculator](https://atoneplace.net/tools/dog-age-calculator/) — A dog's age in human years, using the research formula rather than multiplying by seven.
- [Discount calculator](https://atoneplace.net/tools/discount-calculator/) — Find the sale price and how much you save, including stacked discounts and tax.
- [Days between dates](https://atoneplace.net/tools/days-between-dates/) — Exact days, weeks, months and working days between two dates.
- [Area and volume calculator](https://atoneplace.net/tools/area-volume-calculator/) — Area, perimeter, volume and surface area for the common shapes and solids.
- [Cat age calculator](https://atoneplace.net/tools/cat-age-calculator/) — A cat's age in human years, using the veterinary life-stage mapping.
- [Tile calculator](https://atoneplace.net/tools/tile-calculator/) — How many tiles a floor or wall needs, including cuts and breakage.
- [Concrete calculator](https://atoneplace.net/tools/concrete-calculator/) — Concrete volume for a slab, footing or post hole, in cubic metres and bags.
- [Electricity cost calculator](https://atoneplace.net/tools/electricity-bill-calculator/) — What an appliance costs to run, per hour, day, month and year.
- [Water intake calculator](https://atoneplace.net/tools/water-intake-calculator/) — How much water to drink a day, based on the actual reference intakes.
- [Quadratic equation solver](https://atoneplace.net/tools/quadratic-equation-solver/) — Solve ax² + bx + c = 0, including complex roots, with the working shown.
- [Statistics calculator](https://atoneplace.net/tools/statistics-calculator/) — Mean, median, mode, standard deviation, quartiles and outliers from a list of numbers.
- [Triangle solver](https://atoneplace.net/tools/triangle-calculator/) — Solve any triangle from three known values, with area, perimeter and all angles.
- [Ohm's law calculator](https://atoneplace.net/tools/ohms-law-calculator/) — Voltage, current, resistance and power — give any two, get the other two.
- [Molar mass calculator](https://atoneplace.net/tools/molar-mass-calculator/) — Molecular weight from a chemical formula, with the per-element breakdown.
- [Flooring calculator](https://atoneplace.net/tools/flooring-calculator/) — How many packs of laminate, vinyl or engineered wood a room needs.
- [Profit margin calculator](https://atoneplace.net/tools/profit-margin-calculator/) — Margin, markup and the price needed to hit a target margin.
- [Running pace calculator](https://atoneplace.net/tools/pace-calculator/) — Pace, time and distance — give any two and get the third, with split times.
- [Prime number checker](https://atoneplace.net/tools/prime-number-checker/) — Test whether a number is prime, and get its factors if it is not.
- [Permutations and combinations](https://atoneplace.net/tools/permutation-combination-calculator/) — nPr, nCr, factorials, and whether order matters.
- [Unit price comparator](https://atoneplace.net/tools/unit-price-comparator/) — Compare packs of different sizes and prices to find which is genuinely cheaper.
- [Wire gauge and voltage drop](https://atoneplace.net/tools/wire-gauge-calculator/) — AWG to mm², current capacity and voltage drop over a run.
- [Brick and block calculator](https://atoneplace.net/tools/brick-calculator/) — How many bricks or blocks a wall needs, with mortar quantities.
- [Inflation calculator](https://atoneplace.net/tools/inflation-calculator/) — What an amount is worth after years of inflation, in both directions.
- [Fuel cost calculator](https://atoneplace.net/tools/fuel-cost-calculator/) — Cost of a journey from distance, fuel economy and fuel price.
- [TV size and viewing distance](https://atoneplace.net/tools/tv-viewing-distance/) — How far to sit from a television, or what size fits the distance you have.
- [GCD and LCM calculator](https://atoneplace.net/tools/gcd-lcm-calculator/) — Greatest common divisor and least common multiple of any set of numbers.
- [Speed, acceleration and momentum](https://atoneplace.net/tools/physics-motion-calculator/) — Velocity, acceleration, momentum, force and the equations of motion.
- [Energy and power calculator](https://atoneplace.net/tools/energy-power-calculator/) — Kinetic and potential energy, work, power, and what they cost in electricity.
- [Pressure and density calculator](https://atoneplace.net/tools/pressure-density-calculator/) — Pressure from force and area, fluid pressure with depth, density and buoyancy.
- [Dilution and concentration calculator](https://atoneplace.net/tools/dilution-calculator/) — C₁V₁ = C₂V₂, plus percentage, molarity and ppm conversions.
- [Luggage and backpack weight](https://atoneplace.net/tools/luggage-weight-calculator/) — Track pack weight against airline limits and the carry percentage of your body weight.
- [Aspect ratio calculator](https://atoneplace.net/tools/aspect-ratio-calculator/) — Scale a width or height while keeping the ratio, and identify the ratio of any size.
- [Roof pitch calculator](https://atoneplace.net/tools/roof-pitch-calculator/) — Convert between roof pitch in degrees, ratio and percentage, and get rafter length.
- [Pixel density (PPI) calculator](https://atoneplace.net/tools/pixel-density-calculator/) — Pixels per inch from resolution and screen size, with viewing distance guidance.
- [Gear ratio and belt length](https://atoneplace.net/tools/gear-ratio-calculator/) — Gear ratios, output speed and torque, and belt length between two pulleys.
- [Aquarium volume and stocking](https://atoneplace.net/tools/aquarium-volume-calculator/) — Tank volume from its dimensions, with the real volume after substrate and displacement.
- [Meeting cost calculator](https://atoneplace.net/tools/meeting-cost-calculator/) — What a meeting costs in salary time, per hour and per year if it recurs.
- [Wallpaper calculator](https://atoneplace.net/tools/wallpaper-calculator/) — How many rolls of wallpaper a room needs, allowing for pattern repeat.
- [Shelf spacing and load calculator](https://atoneplace.net/tools/shelf-spacing-calculator/) — Even shelf spacing for a given height, and whether the span will sag.

## Text tools

- [Word and character counter](https://atoneplace.net/tools/word-counter/) — Words, characters, sentences, paragraphs and reading time, counted as you type.
- [Typing speed test](https://atoneplace.net/tools/typing-speed-test/) — Measure words per minute and accuracy on a one, two or five minute test.
- [Remove duplicate lines](https://atoneplace.net/tools/remove-duplicate-lines/) — Strip repeated lines from a list, keeping the first occurrence of each.
- [Sort lines alphabetically](https://atoneplace.net/tools/sort-lines/) — Sort a list of lines A–Z, Z–A, by length, or numerically.
- [JSON formatter and validator](https://atoneplace.net/tools/json-formatter/) — Pretty-print, minify and validate JSON, with the exact position of any error.
- [Text compare](https://atoneplace.net/tools/text-diff/) — Compare two blocks of text and see which lines were added, removed or changed.
- [Regex tester](https://atoneplace.net/tools/regex-tester/) — Test a regular expression against sample text, with matches and capture groups shown.
- [Case converter](https://atoneplace.net/tools/case-converter/) — Convert text between upper, lower, title, sentence, camel, snake, kebab and other cases.
- [Remove empty lines](https://atoneplace.net/tools/remove-empty-lines/) — Delete blank lines from a block of text, optionally collapsing runs to one.
- [Find and replace](https://atoneplace.net/tools/find-and-replace/) — Replace every occurrence of a string in pasted text, with optional regex.
- [Readability checker](https://atoneplace.net/tools/readability-checker/) — Flesch Reading Ease and grade level, with sentence length and passive voice flagged.
- [Text cleaner](https://atoneplace.net/tools/text-cleaner/) — Strip emojis, numbers, punctuation, extra spaces or line breaks from pasted text.
- [XML, YAML, SQL and CSS formatter](https://atoneplace.net/tools/code-formatter/) — Pretty-print and minify XML, YAML, SQL, CSS and HTML.
- [EXIF viewer and metadata remover](https://atoneplace.net/tools/exif-viewer/) — See what metadata a photo carries, including GPS, and strip it out.
- [Base64 encoder and decoder](https://atoneplace.net/tools/base64-encoder/) — Encode text to Base64 or decode it back, entirely in your browser.
- [URL encoder and decoder](https://atoneplace.net/tools/url-encoder/) — Percent-encode text for use in a URL, or decode it back.
- [JWT decoder](https://atoneplace.net/tools/jwt-decoder/) — Decode a JSON Web Token to read its header, payload and expiry.
- [Shuffle lines](https://atoneplace.net/tools/shuffle-lines/) — Randomly reorder a list of lines, using a proper unbiased shuffle.
- [Reverse text](https://atoneplace.net/tools/reverse-text/) — Reverse text by character, by word, or reverse the order of lines.
- [ROT13, Caesar and Morse](https://atoneplace.net/tools/cipher-tool/) — Encode and decode ROT13, Caesar shifts, Morse code and Atbash.
- [Markdown table generator](https://atoneplace.net/tools/markdown-table-generator/) — Turn CSV or tab-separated data into a formatted Markdown table.
- [Upside-down and mirror text](https://atoneplace.net/tools/upside-down-text/) — Flip text upside down, mirror it, or convert it to other Unicode letterforms.
- [Text splitter and list formatter](https://atoneplace.net/tools/text-splitter/) — Split into sentences or paragraphs, number lines, and convert between bullet styles.
- [SVG optimiser and minifier](https://atoneplace.net/tools/svg-optimizer/) — Strip editor metadata, shorten numbers and minify an SVG.
- [URL slug generator](https://atoneplace.net/tools/slug-generator/) — Turn a title into a clean, lowercase, hyphenated URL slug.
- [Typographic scale and line height](https://atoneplace.net/tools/typography-scale-calculator/) — Build a modular type scale, and get sensible line height and measure.
- [HTML escape and unescape](https://atoneplace.net/tools/html-escape/) — Convert characters to HTML entities so markup displays as text, or convert back.
- [Keyword density checker](https://atoneplace.net/tools/keyword-density-checker/) — Count word and phrase frequency in text, with density as a percentage.

## Generators

- [Password generator](https://atoneplace.net/tools/password-generator/) — Generate strong random passwords in your browser, with the entropy shown.
- [Merge PDF files](https://atoneplace.net/tools/pdf-merge/) — Combine several PDFs into one, in the order you choose.
- [QR code generator](https://atoneplace.net/tools/qr-code-generator/) — Make a QR code for a link, text, WiFi network or contact details, and download it as SVG.
- [Image resizer](https://atoneplace.net/tools/image-resizer/) — Resize an image to exact dimensions or a percentage, in your browser.
- [Split and extract PDF pages](https://atoneplace.net/tools/pdf-split/) — Pull out a page range, split into single pages, or delete pages.
- [Random number generator](https://atoneplace.net/tools/random-number-generator/) — Random numbers in any range, plus dice, coin flips and a shuffled pick from a list.
- [Random picker and team generator](https://atoneplace.net/tools/random-picker/) — Pick a winner from a list, split into teams, or generate a random order.
- [Image crop, rotate and flip](https://atoneplace.net/tools/image-crop-rotate/) — Crop to an aspect ratio, rotate in 90° steps, or mirror an image.
- [Lorem ipsum generator](https://atoneplace.net/tools/lorem-ipsum-generator/) — Generate placeholder text by paragraphs, sentences or words.
- [Meta tag generator](https://atoneplace.net/tools/meta-tag-generator/) — Generate title, description, canonical, Open Graph and Twitter Card tags.
- [Printable graph paper](https://atoneplace.net/tools/graph-paper-generator/) — Generate and print squared, dotted, isometric, hexagonal or lined paper.
- [Dice roller](https://atoneplace.net/tools/dice-roller/) — Roll any dice notation — 2d6, 4d6 drop lowest, d20 with advantage.
- [Pixelate or blur part of an image](https://atoneplace.net/tools/image-redact/) — Cover faces, names or numbers by pixelating or blacking out a region.
- [Rotate and reorder PDF pages](https://atoneplace.net/tools/pdf-rotate/) — Rotate individual pages or the whole document, and reorder pages.
- [Hash generator](https://atoneplace.net/tools/hash-generator/) — SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text, computed in your browser.
- [Make square and add padding](https://atoneplace.net/tools/image-padding/) — Make an image square without cropping, add a border, or add a print safe margin.
- [UUID generator](https://atoneplace.net/tools/uuid-generator/) — Generate random version 4 UUIDs in your browser.
- [robots.txt generator](https://atoneplace.net/tools/robots-txt-generator/) — Build a robots.txt with crawler rules, AI bot access and a sitemap line.
- [Schema markup generator](https://atoneplace.net/tools/schema-markup-generator/) — Generate JSON-LD structured data for an organisation, article, FAQ, product or local business.
- [Username and name generator](https://atoneplace.net/tools/username-generator/) — Generate usernames, project names or pronounceable fake words.
- [Decision maker](https://atoneplace.net/tools/decision-maker/) — Yes or no, or a weighted decision matrix scoring options against criteria.
- [Add page numbers to a PDF](https://atoneplace.net/tools/pdf-page-numbers/) — Stamp page numbers onto an existing PDF, with position and start value.
- [Printable ruler and scale check](https://atoneplace.net/tools/printable-ruler/) — Print an accurate ruler in centimetres or inches, with a calibration check.

## Colour

- [Colour converter](https://atoneplace.net/tools/color-converter/) — Convert a colour between HEX, RGB, HSL and CMYK, with a contrast check against black and white.
- [Random colour and palette generator](https://atoneplace.net/tools/random-color-generator/) — Generate random colours or a harmonious palette, with contrast checked.
- [Colour shades and gradient generator](https://atoneplace.net/tools/color-shades-generator/) — Build a tint and shade scale from one colour, or a gradient between two.
- [Extract colours from an image](https://atoneplace.net/tools/image-color-extractor/) — Pull the dominant colours out of an image as a palette.

## Time

- [Reaction time test](https://atoneplace.net/tools/reaction-time-test/) — Measure visual reaction time over five attempts, with the median reported.
- [Time zone converter and meeting planner](https://atoneplace.net/tools/timezone-converter/) — Convert a time between zones and find the overlap for a meeting.
- [Stopwatch and countdown timer](https://atoneplace.net/tools/stopwatch-timer/) — A stopwatch with laps and a countdown timer, running in your browser tab.
- [Click speed test](https://atoneplace.net/tools/click-speed-test/) — Clicks per second over a timed burst of 1, 5, 10 or 60 seconds.
- [Countdown to a date](https://atoneplace.net/tools/countdown-timer/) — Days, hours and minutes until any date, with the working days counted separately.
- [Leap year and week number](https://atoneplace.net/tools/leap-year-checker/) — Whether a year is a leap year, the ISO week number, and the day of the week for any date.
- [Metronome and tone generator](https://atoneplace.net/tools/metronome-tone-generator/) — A metronome with tap tempo, and a tone generator for any frequency.
- [Reply delay timer](https://atoneplace.net/tools/reply-timer/) — Work out when to send a reply if you are matching the delay you were given.

## Converters

- [Image format converter and compressor](https://atoneplace.net/tools/image-converter/) — Convert between JPEG, PNG and WebP, and compress with a quality slider.
- [Number base converter](https://atoneplace.net/tools/number-base-converter/) — Convert between binary, octal, decimal, hexadecimal and any base from 2 to 36.
- [Unix timestamp converter](https://atoneplace.net/tools/unix-timestamp-converter/) — Convert between Unix timestamps and human dates, in seconds or milliseconds.
- [SVG to PNG converter](https://atoneplace.net/tools/svg-to-png/) — Rasterise an SVG at any size, with transparency preserved.
- [Cron expression parser](https://atoneplace.net/tools/cron-expression-parser/) — Explain a cron expression in plain English and show the next run times.
- [Mouse sensitivity and FOV converter](https://atoneplace.net/tools/mouse-sensitivity-converter/) — Convert sensitivity between games so your aim carries across, and convert field of view.
- [CSV to JSON converter](https://atoneplace.net/tools/csv-to-json/) — Convert CSV to a JSON array of objects, or JSON back to CSV.
- [Screen resolution and display info](https://atoneplace.net/tools/screen-resolution-checker/) — Your screen resolution, viewport size, pixel ratio, colour depth and refresh rate.