合计
hé jì · HSK 7
to add up the total
🧮 合 = combine + 计 = count/calculate, so combine-and-count = add up the total
合 carries the sense of joining or combining; 计 means to count, calculate, or plan. Joined together they mean to total things up, or by extension to take everything into account when considering something.
合 — 乛 (lid/roof) + 口 (mouth)
Originally a pictograph of a lidded vessel — a cover (亼) closing over an opening (口) — giving the core sense of 'come together, join, fit.' From 'fit/match' it extended to 'combine, unite, agree' and to measure-word uses. The reading hé reflects this 'joining' meaning.
计 — speech radical 讠 (言) + ten 十
计 is a semantic compound: 言 'speech/words' plus 十 'ten', suggesting counting or reckoning aloud. The original sense was to calculate or tally numbers, which extended to 'plan, scheme, plot' — any kind of mental reckoning. Modern uses like 计算 (calculate) and 计划 (plan) preserve both threads.