Hobbies & Makers calculators

A focused hub of formula-based tools in the hobbies & makers category. Each page includes the calculator, formula, assumptions, and related tools.

Updated 5 Aug 2026

Astrophotography Bortle Exposure Equivalency Calculator

Compare Bortle or SQM sky brightness levels and estimate equivalent integration time, sub-exposure adjustment, and SNR impact for astrophotography.

Updated 4 Aug 2026

Beekeeping Sugar-Syrup Calculator

Estimate sugar and water for bee syrup by target volume or sugar on hand, including finished yield, feeder fills, and container fit.

Updated 4 Aug 2026

Cross-Stitch Fabric and Thread Calculator

Estimate cross-stitch fabric size, margins, floss skeins, needle size, and stitching time from pattern stitches, fabric count, coverage, and colors.

Updated 4 Aug 2026

Disc Golf Disc Speed Selector

Calculate recommended disc speed, control-speed range, disc class, and stability suggestion from your max flat-ground throw distance.

Updated 14 Aug 2026

Film Reciprocity Failure Calculator

Calculate film reciprocity failure correction from metered exposure time, film profile, p-factor exponent, threshold, and bracketing range.

Updated 5 Aug 2026

Houseplant Repotting and Soil Mix Calculator

Calculate the next pot size and soil mix ingredient volumes for tropical houseplants, aroids, succulents, orchids, ferns, and propagation.

Updated 14 Aug 2026

Knot Strength Retention Calculator

Calculate estimated knot-retained rope strength, working load, dynamic-adjusted working load, and load utilisation from rope rating and knot type.

Updated 5 Aug 2026

Miniature Painting Dilution and Airbrush PSI Calculator

Calculate a starting thinner ratio, drop recipe, PSI range, and spray distance for airbrushing miniatures, primers, varnishes, glazes, and terrain.

Updated 15 Aug 2026

Mushroom Spawn-to-Substrate Ratio Calculator

Estimate mushroom spawn needed from substrate weight, species, grow method, spawn percentage, substrate moisture, container count, and biological efficiency.

Updated 4 Aug 2026

Resin Print Exposure Time Scaler

Estimate a new resin exposure time from a known-good exposure and target layer height.

Updated 4 Aug 2026

Wood Movement Predictor

Calculate across-grain wood movement, shrinkage, swelling, and recommended allowance for panels, tabletops, drawers, and doors.