WCAG contrast ratio between two hex colors with AA and AAA pass/fail for normal and large text.

Convert a unix timestamp or ISO time to ISO, local time in any IANA zone, weekday, ISO week and relative time.

Baker's percentages and hydration from a gram formula, counting sourdough starter, with scaling to a flour or dough weight.

Inspect a UUID: valid or not, version (1-8), variant, and the embedded timestamp for v1, v6 and v7 UUIDs.

USDA egg sizes: weight per egg, and how many eggs of one size equal a recipe's count in another (for example mediums for large).

Coffee grams for your water (or water for your grams) by method: drip, pour-over, press, espresso, cold brew; rough caffeine.

Beer, wine and cider alcohol by volume from original and final gravity, with both standard formulas and attenuation.

Approximate grams per cup, tablespoon and teaspoon for baking ingredients, with the published sources and spread.

Brine math: salt grams for a target strength, or the strength of a brine, with table and kosher salt spoon amounts.

Generate a CSS clamp() that scales a size linearly between a min and max viewport width, in rem, with the exact slope.

USDA minimum internal cooking temperature for a food (poultry, ground meat, steaks, fish, eggs), plus a check of your reading.

CSS box model sizes: content, padding, border and margin boxes from a width and height under content-box or border-box.

Column and span widths for an N-column grid from container width, columns and gutter, or the container for a column width.

Convert a CSS length between px, rem, em, pt, pc, in, cm, mm, Q, vw, vh, vmin, vmax and % with your root and viewport sizes.

CSS selector specificity (ids, classes, types) per Selectors Level 4, including :is(), :not(), :where() and :has(); compare two.

Baking pan volume in cups and mL for round, square and rectangular pans, and the recipe scale factor from one pan to another.

Convert oven temperatures between Celsius, Fahrenheit and gas marks, with the fan-oven setting and an oven-heat name.

Estimate characters per line from column width and font size and rate it for readability (45-75 ideal, WCAG max 80).

Screen pixel density (PPI) from resolution and diagonal, physical size, CSS viewport at a device pixel ratio, and image widths.

Check a click or touch target against WCAG 2.2 target size (24 px AA, 44 px AAA) including the spacing exception.