Guides
Written explanations of the calculations behind the tools on this site — the principles themselves, not instructions for the calculators. Each one stands on its own.
- Baker's percentage and hydration: how bread recipes actually scale
Why flour is always 100%, what hydration predicts about a dough, why the starter changes the real figure, and how to scale a recipe from either flour weight or target dough weight.
- Lye, superfat, and why soap recipes are calculated rather than copied
Saponification, SAP values, why swapping oils without recalculating is dangerous, what superfat really does, and the three incompatible ways recipes express water.
- Clay shrinkage: why your pot comes out smaller than you made it
The two separate shrinkages a ceramic piece goes through, how to measure your own clay's rate with a test bar, and the formula for sizing a piece to finish at a target dimension.
- Epoxy mix ratios and exotherm: why “a bit more hardener” ruins a pour
Why epoxy's ratio is stoichiometry rather than a catalyst dose, how weight and volume ratios differ, and why deep pours overheat, crack and occasionally smoke.
- Aquarium stocking: what bioload actually means
Why the inch-per-gallon rule misleads, how the nitrogen cycle sets the real limit, and the behavioural constraints — schooling, territory, footprint — that volume never captures.
- What your photos reveal: EXIF, GPS, and when to strip it
What EXIF, IPTC and XMP actually store, which sharing paths preserve location data, the three ways to remove it, and the cases where keeping metadata is the right call.