Free web tools that just work

Games with a global high score board — your run is ranked against everyone else who has played.

Games to play for their own sake — puzzles, sandboxes and classics, with no score to chase and nobody to beat.

Trackers, pairings, generators and probability for the games you play away from the screen.

Poker odds, blackjack strategy, house edges and deck probability — the maths behind the cards.

Build printable puzzles from your own words and pictures, every one checked to have an answer.

Weird headlines first, then the serious stuff.

Notes, lists, and handy everyday helpers.

Format, encode, and inspect text and data.

Convert between units, colors, and formats.

Generate passwords, IDs, hashes, and more.

Statistics, fractions, and everyday math.

Mortgage, loan, interest, and everyday money math.

Quick health and fitness calculators.

Work out ages, durations, and dates.

Dictionary, thesaurus, and rhyme finder.

Chord finders, tuners, and a metronome.

Convert audio files and measure sound.

Compress, resize, and convert images.

Generate CSS for gradients, shadows, and more.

Meta tags, robots.txt, and other site helpers.

Weather forecasts and fun outdoor risk estimates.

Fishing calculators, hunting references, and outdoors know-how.

Trip planning for hikers and backpackers — time, difficulty, and what to carry.

Grade conversion and the anchor and fall physics every leader is taught.

Ski and snowboard setup, avalanche terrain, and how cold that chairlift really is.

Diving, surfing, paddling and sailing — the planning numbers that matter.

Tanks, propane, power and payload — the numbers that decide how long you can stay out.

Tyre pressure, gearing and the numbers that decide how a bike actually rides.

Resistor codes, Ohm's law and the reference values every bench needs within reach.

Wire sizing, voltage drop and solar planning, with the code rules that decide the answer.

Density altitude, performance and the wind maths, for study and planning alongside the aircraft own charts.

Speeds, feeds, threads and weld figures, with the corrections the shop tables leave out.

Framing, concrete and masonry layout, with the geometry the rules of thumb quietly get wrong.

Board feet, cut lists and joinery — starting with how much of the wood you paid for actually arrives.

Shrinkage, glaze batches and vessel volumes — the studio arithmetic that decides whether a lid fits.

Wax weights, fragrance loads and burn times — starting with why an 8 oz jar does not hold 8 oz of wax.

Blank lengths, aspect ratios and thread paths — the geometry that decides whether a ring closes at the size you wanted.

Scale ratios, material volumes and coverage — starting with why a step up in scale is modest in length and enormous in everything else.

Boxes cut from sheets, sheets wrapped round boxes and sheets folded into books — where the exact answers are prettier than the rules of thumb.

Baseball, basketball and football arithmetic — starting with how few of these rate stats are the percentages their names promise.

Staggers, race predictions and mileage ramps — where the exact arithmetic keeps disagreeing with the rule of thumb.

What a scoring system does to a small edge — and it is almost always more than anyone expects.

A barbell is a discrete instrument and the arithmetic around it pretends otherwise — starting with the weights you cannot actually load.

A score with mixed units, a slope through two points, and a hundred that is not a hundred.

Trade constants that turn out to be derivations — and the denominators that decide what a number actually means.

Exponential decay and dilution are the same arithmetic — and both have an off-by-one hiding in them.

Rules of thumb that hold at one distance and one magnification — and the variable each of them is really tracking.

Wheels, alignment and fasteners — where the units quietly disagree and a spec carried across changes what it means.

Recipe ratios measured against one ingredient rather than the whole — starting with what "percent" is a percent OF.

Seed, water, feed and mow — with the rates and the timing that decide whether any of it works.

Slicer settings, filament and fit — with the arithmetic behind the advice rather than the advice on its own.

Gearing, suspension, premix, stopping distances, recovery loads and the angles that decide what you can drive over.

Pickers, spinners and generators for when something has to be decided by chance.

Handicap, strokes gained, club gapping and the rest of the numbers that actually change a round.

Scorekeepers, checkout charts, oil patterns and table geometry for the indoor sports.

Flight numbers, disc selection, and the lawn games that end up alongside them.

Metal detecting, coin composition, melt value and rockhounding.

Binoculars, nest boxes, feeders and the lists that make a season worth remembering.

Plan trips and search flights.

Rating lookups, PGN and FEN tools, a tournament clock, and drills for the things strong players never look up.

Build a resume that reads the way software extracts it, and search the boards the way recruiters do.

Cutting geometry, yardage and fabric arithmetic — the numbers that decide whether a piece fits the bolt.