Weaving Calculators - Janet Dawson provides multiple online tools for sett and weaving calculations
Brassard Cotton Color Numbers - all colors listed with RGB and hex numbers
Draft Color Editor - test different colors on any draft [available with subscription to Handweaving.net]
Weaving Color Mixer - terrific tool from Tien Chiu that illustrates how 2 colors [your choice] mix in various weaves
Draft Editor plus hundreds of weaving drafts for 4 & 8 shafts - [available with subscription to Handweaving.net]
Random Stripe Generator - choose colors and width of stripes; intended for knitters but works for weaving
Inkle Loom Pattern Generator - using a fill-in form you can try different patterns with lots of colours and see how it will look.
Reed Substitution Chart - figure out how to thread the reed when you don't have the most appropriate reed
Reed Substitution Tool - a simple form from Jane Stafford tells you what to thread with the reed you have
Treadle Reducer - a simple form that helps you reduce the number of treadles a pattern uses when you don't have enough
Average Sett Calculator - for mixed warps; Janet Dawson
Master Sett Chart - from Jane Stafford; lists suggested setts for cotton, linen, bambu, silk and wool.
Master Yarn Chart - from Interweave Press; lists many yarns with yards per pound and sett. Free but must register.
Weaving Project Calculator - from Janet Dawson
Weaving Calculator - a helpful tool to calculate your warp and weft yardage, as well as your project costs.