The super-slow conversion of the U.S. to metric (2025)

Number bases and divisibility

• Some argue metric’s “worst flaw” is base‑10, claiming base‑12 (or even 60) is mathematically superior because it divides cleanly by more factors (2,3,4,6).
• Others counter that as long as people count and write numbers in base‑10, base‑10 units are simpler: shifting decimal points is trivial, while base‑12 would require rewriting all numbers or messy conversions.
• Finger‑counting schemes for 12 (knuckles, joints) and binary/hex counting on fingers are discussed, but most see them as curiosities rather than practical reform paths.

Customary vs metric in practice

• Thread notes the distinction between U.S. customary and British imperial (e.g., different gallons, pints, cups), and the UK’s own hybrid system (miles and pints, but liters and metric engines).
• In the U.S., science and most advanced engineering are described as almost entirely metric; consumer‑facing domains (construction, domestic measurements, road signs, weather) remain heavily customary.
• Many industries are already mixed: metric components with imperial interfaces, metric plywood thicknesses, metric car parts, but imperial‑sized fasteners, pipes, and lumber.

Perceived “naturalness” of units

• Several people say feet/inches and Fahrenheit feel more intuitive for “human‑scale” tasks, especially construction and weather.
• Others insist that “naturalness” is just familiarity; metric users find centimeters, meters, and Celsius equally or more intuitive.
• Arguments that imperial fractions (1/2, 1/4, 1/8, etc.) are convenient are met with counter‑arguments that decimal whole millimeters avoid fraction arithmetic altogether.

Temperature scales debate

• Fahrenheit defenders like a ~0–100 °F “everyday outdoor range” and finer whole‑degree granularity.
• Celsius defenders like 0 °C as freezing and 100 °C as boiling; for everyday weather they think in rough 5 °C steps and don’t care about decimals.
• Both sides concede that habit and climate shape intuition more than any inherent superiority.

Engineering, construction, and tooling

• Mixed‑unit specs (mm bores, inch depths, metric threads, imperial set screws) are common and widely hated.
• Fasteners, gauges, drill sizes, pipe “nominal” sizes, and multiple ounce/pound definitions are cited as especially chaotic.
• Some note that many tolerances and “nominal” dimensions make the underlying unit system less critical internally, but crucially confusing at interfaces.

Cooking, groceries, and daily life

• Packaging in North America often carries both systems; some categories (liquor, many sodas) are effectively metric already.
• Several strongly prefer grams and scales for baking; others insist cups/spoons are faster and “accurate enough.”
• Everyday U.S. users report a pragmatic hybrid: metric for small/precise quantities, customary for body weight, height, room sizes, and driving.

Cultural, political, and historical factors

• The 1970s metric push, associated optimism, and later rollback (including abolition of the U.S. Metric Board) are recalled with mixed nostalgia and blame.
• Resistance is seen as cultural identity and inertia rather than rational evaluation; some explicitly value imperial as “warm,” idiosyncratic, and historically rich.
• Opinions on change split: some think a federal mandate could force a rapid transition; others think there’s no compelling benefit for current adults, so only slow, market‑driven convergence is likely.