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Using a Stopwatch

Everything a new coach or timer needs: the buttons, timing a swimmer accurately, and calculating stroke rate, stroke count, and pace — with drills to practice each skill.

In This Guide
  1. Anatomy of a Stopwatch
  2. Timing a Swimmer
  3. Calculating Stroke Rate
  4. Counting Strokes
  5. Calculating Pace
  6. Practice the Skills
01

Anatomy of a Stopwatch

Layouts vary by brand, but nearly every two-button coaching stopwatch follows this pattern:

00:00 .0 2 1 3
1Start/Stop — press once to start the clock running, press again to stop it.
2Lap/Split — records the current time without stopping the clock, so you can catch each rep in a set.
3Display — usually shows minutes:seconds.tenths. Some watches switch to a memory/review mode with the same button held down.

Reset is typically a separate button on the underside, or you hold Start/Stop for a couple of seconds once the watch is stopped — check your specific model, since this is the one that varies most between brands.

02

Timing a Swimmer

The goal is consistency — the same trigger and the same stopping point every time, so times are comparable across a season.

Good to know

Human reaction time adds roughly 0.2–0.3 seconds of error on both the start and the stop. That's fine for tracking practice progress, but it's why official race times come from touchpads and automatic timing systems, not a coach's stopwatch.

→ Practice this skill: Lap Splits Drill
03

Calculating Stroke Rate

Stroke rate is how many arm cycles a swimmer completes per minute. A cycle is one full arm cycle — e.g. the right hand entering the water, all the way around to the right hand entering again.

The 3-cycle method

  1. Pick a reference point — e.g. the swimmer's right hand entering the water.
  2. Start your stopwatch on one entry.
  3. Stop it on the fourth entry of that same hand — that's 3 complete cycles.
Entry 1 start watch Entry 4 stop watch Entry 2 Entry 3 3 cycles
Formula
Stroke rate (cycles/min) = 180 ÷ seconds for 3 cycles
3 cycles × 60 seconds, divided by the time it actually took — same math, shortcut version.
Worked example

3 cycles take 4.2 seconds → 180 ÷ 4.2 ≈ 43 cycles per minute.

→ Practice this skill: Stroke Rate Drill
04

Counting Strokes

Stroke count is simply how many strokes a swimmer takes to complete one length — a different number from stroke rate, and just as useful. Where stroke rate measures tempo, stroke count measures efficiency: how much distance a swimmer covers per stroke.

How to count

  1. Start counting from the first stroke after the push-off — not the push-off or the glide itself.
  2. Count each individual arm entry (left and right both count) through to the touch.
  3. Some coaches count full cycles instead of single-arm entries — either works, just stay consistent within a squad so counts are comparable swimmer to swimmer.
Worked example

A swimmer takes 16 strokes to cross a 25m length.

Distance per stroke

Pair stroke count with the length swum to see how far each stroke is actually carrying the swimmer:

Formula
Distance per stroke = length ÷ stroke count
Longer distance per stroke generally means a more efficient pull — up to a point; too few strokes can mean over-gliding and losing speed between strokes.
Worked example

25m ÷ 16 strokes = ≈1.56m per stroke.

What to watch for

Stroke count creeping up late in a swim is one of the clearest signs of fatigue — the stroke is shortening even if the rate holds steady. Tracking count and rate together gives a fuller picture than either alone.

→ Practice this skill: Stroke Count Drill
05

Calculating Pace

Pace is time per 100 (metres or yards) — it lets you compare swims of different distances and set training intervals off a single number.

Formula
Pace per 100 = (total seconds ÷ total distance) × 100
Keep distance and pace in the same units — metres with metres, yards with yards.
Worked example

400m in 5:20 (320 seconds) → (320 ÷ 400) × 100 = 80 seconds/100m = 1:20 per 100.

To set a repeat interval, add rest to the goal pace — e.g. pace + 10–15 seconds gives a send-off that's challenging but sustainable across a set.

→ Practice this skill: Lap Splits Drill
06

Practice the Skills

Drill each skill right here — the 3-cycle stroke rate method, counting strokes across a length, and recording lap splits without stopping the clock.

Prefer a distraction-free, full-screen version? Open the standalone Stopwatch Practice tool →

Watch the circle pulse on each simulated hand entry. Press Lap on entry 1, then again on entry 4 — that's 3 full cycles. I'll calculate your measured stroke rate and compare it to the actual simulated rate.

00:00.0
ENTRY
Press Start, then tap Lap on each pulse.

Quick Reference