Find your kind of useful.
674 free tools across 26 categories. Browse a subject, choose a task and get a clear explanation alongside the result.
Food & cooking
25 tools · Recipe scaler, Recipe batch scaling table, Ingredient composition table
Conversions
44 tools · Length converter, Temperature converter, Weight converter
Money & shopping
45 tools · Bill splitter, Unit price calculator, Margin & markup calculator
Health & wellbeing
6 tools · BMI calculator, BMR calculator, TDEE calculator
Outdoors & maps
12 tools · GeoJSON structure inspector, GeoJSON points to CSV, Manning open-channel flow
Weather & air
6 tools · Humidity & dew point, Vapour pressure deficit, Wind chill calculator
Travel & transport
6 tools · Aerodynamic drag & power, EV charging time & cost, Tyre size comparison
Planning & productivity
16 tools · Party seating allocation, Volunteer role rotation, Round-robin fixture maker
Sport & fitness
6 tools · Round-robin tournament schedule, Seeded knockout bracket, League table calculator
Garden & outdoors
20 tools · Square-foot garden grid, Garden sowing date worksheet, Succession planting schedule
Sewing & crafts
20 tools · Knitting shaping row planner, Crochet circle round counts, Quilt block layout planner
Home & DIY
33 tools · Shelf carcass panel cut list, Paver grid and edge-cut plan, Window blind measurement worksheet
Dates & time
30 tools · Date difference, Date range generator, Recurring date planner
Education & study
12 tools · Assignment grade calculator, Required final exam grade, Exam score with negative marking
Music & audio
23 tools · WAV waveform & trimmer, Musical note frequency, Frequency to musical note
Engineering & mechanics
22 tools · Rectangle section properties, Elastic bending stress, Beam deflection curves
Science & engineering
61 tools · Stokes settling velocity, Ideal rocket delta-v, Ideal circular orbit
Statistics & probability
37 tools · Box plot builder, Binomial probability calculator, Poisson probability calculator
Maths & numbers
99 tools · Percentage calculator, Convex hull builder, Closest pair in a point cloud
Text & writing
30 tools · Word & character counter, Text concordance / KWIC, N-gram frequency analyser
Data & CSV
55 tools · CSV dataset diff, CSV rule validator, CSV calculated column
Images & photos
7 tools · Image comparison slider, Image resizer, Image format converter
PDF & files
10 tools · ZIP archive inspector, Merge PDFs, Extract PDF pages
Design & colour
26 tools · 2D point transformation, Bézier curve sampler, Image colour palette extractor
Developer tools
17 tools · JSON Pointer query, JSON Merge Patch, JSON Patch applier
Everyday & games
6 tools · Dice roller, Random list picker, Random group generator