Free · No login · Sources cited
Do the math.
Make the sawdust.
The calculators woodworkers actually need — shelf sag, lathe speeds, segment angles, glue-up layouts — rebuilt for this decade. Every formula shown, every answer instant.
Shelving & Structure
Woodturning
Wood Lathe Speed Calculator
Safe RPM by blank diameter — roughing to sanding, with unbalanced-blank guidance and rim speed shown.
Live · Free
Segmented Turning Calculator
Segment lengths, cut angles, and ring dimensions for bowls and vases.
Coming soon
Boards & Panels
End Grain Cutting Board Calculator
Strip counts, board footage, and glue-up layout for your pattern.
Coming soon
Shop Reference
Router Bit Speed Chart
Max safe RPM by bit diameter — printable shop reference.
Coming soon
Janka Hardness Chart
Sortable hardness ratings for 100+ domestic and exotic species.
Coming soon
Built like a good jig
Every tool here shows its formula and cites its sources — mostly the U.S. Forest Products Laboratory’s Wood Handbook and standard machining references. If a number matters for safety, we say so. Found an error? Tell us and we’ll fix it.