plot, plan, scheme, measure
計 centers on deliberate mental activity: plotting, planning, or scheming, and the act of measuring or calculating that supports such planning.
計 combines 言 (words, speech) with 十, which likely represents a counting or calculating tool, suggesting the idea of measuring or planning through words or numbers.
Words (言) and a counting rod (十) come together: someone is talking through a plan while measuring and calculating. That's plotting and scheming.
For ケイ, imagine a clever plotter named Kay who measures every detail: Kay -> ケイ, and her words (言) and calculations (十) are always precise.
plan; project; schedule; scheme; program; programme
plan; design; layout
calculation; computation; reckoning; counting; adding up; working out; figures
clock; watch; timepiece
plan
sum total; total amount
extra; more; too much; too many; excessive; superfluous; spare; surplus
statistics
accounting; finance; account; reckoning
cumulative total; accumulated total; total up to now
to measure; to weigh; to survey; to time (sound, gauge, estimate)
wristwatch; watch
totalization; totalisation; aggregation; tally (e.g. of votes); adding up; summing up
measuring; measurement
household economy; family finances
accountant
including (a cost) in a total calculation; appropriating (a sum of money); recording; allocating; booking
livelihood; living
estimate; estimation
measuring; weighing
total; sum total; total amount
meter; gauge
hourglass; sandglass
Board of Audit
(clinical) thermometer
paymaster; accountant
arrangement
bill (at a restaurant); check
budget bureau
fiscal year
certified public accountant
family planning
household account book
thermometer
thermometer
alarm clock
spreadsheet
unfathomable; inestimable; immeasurable
planned; scheduled; systematic
city planning; urban planning; town planning