Several parts combine into one character.

計 combines 言 (speech) with 十 (ten) — counting from one to ten (十) aloud (言). From counting and reckoning came "to count, to measure, to plan, a plan."

The simplified form is 计, with 言 reduced to the speech radical 讠 — the form splits by mode.

Korean hanja-sound "gye": 計劃 (gyehoek, plan), 計算 (gyesan, calculation), 設計 (seolgye, design), 時計 (sigye, clock), 會計 (hoegye, accounting), 統計 (tonggye, statistics). It also means "scheme / stratagem" — the 計 of 三十六計 (the Thirty-Six Stratagems).

Mandarin: jì, 4th tone. 计划 (jìhuà, plan), 计算 (jìsuàn, to calculate), 设计 (shèjì, design), 会计 (kuàijì, accounting), 统计 (tǒngjì, statistics), 计算机 (jìsuànjī, computer). Japanese: on-reading ケイ (kei), kun はか.る (hakaru). 計画 (keikaku, plan), 計算 (keisan, calculation), 時計 (tokei, clock), 合計 (gōkei, total), 会計 (kaikei, accounting). The Japanese 時計 (tokei, clock) is a special reading (jukujikun).

Memory aid: counting to ten (十) aloud (言) — to reckon and to plan.