Paritian

Mathematics

Clock Angle Calculator

Angle between the hour and minute hands of a clock at any time, and how long until they next overlap.

Results

Angle between the hands (smaller) 7.50 °
The other angle 352.50 °
Minutes until the hands next overlap 1.36 min

What this tool does

The minute hand turns 6° a minute, but the hour hand also moves — half a degree a minute — which is the detail most people miss: at 3:15 the hands are not on top of each other but 7.5° apart. That is why the angle is |30 h − 5.5 m|. The hands overlap 11 times in twelve hours, every 65 min 27 s, not every hour.

Formula

θ = |30 × h − 5.5 × m| · smaller angle = min(θ, 360° − θ)

Variables

SymbolMeaningUnit
hHourh
mMinutesmin
AAngle between the hands (smaller)°
BThe other angle°
NXMinutes until the hands next overlapmin

Worked example

  • Hour3 h
  • Minutes15 min
  • Angle between the hands (smaller)7.50 °
  • The other angle352.50 °
  • Minutes until the hands next overlap1.36 min

Limitations

  • The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.
  • Mixing units is the most common source of error. Convert every input to the units shown next to each field before calculating.