CBL Sports — Swimmer Education Series

How to Read & Use a Pace Clock

A guide for youth swimmers and their parents

1. What Is a Pace Clock?

A pace clock is the large round clock you see at the end of each swimming lane. It is one of the most important tools in swim practice. Unlike a regular clock that tells you the time of day, a pace clock helps swimmers track how long each swim takes and when to start the next one.

Most pace clocks count from 0 to 60 seconds and then start over. Some pools have digital pace clocks; others have the classic analog style with a sweeping hand. Both work the same way — once you understand one, you understand both!

Did You Know?

Pace clocks were invented so that swimmers in different lanes can all start and stop at the same reference point — even without a coach blowing a whistle every few seconds.

2. Reading the Clock

The Analog (Round) Pace Clock

The face shows numbers from 0/60 at the top, going clockwise to 5, 10, 15 … 55.

The sweep hand moves continuously — one full revolution per minute.
Numbers mark every 5 seconds; small tick marks show individual seconds in between.
Top of the clock (12 o'clock) = 0 / 60 seconds. This is the most common "go" position.
The hand position when you touch the wall = your split time.

The Digital Pace Clock

Digital Pace Clock

Digital clocks show elapsed seconds as a number directly — no hand to follow. They count up from 0:00 to 1:00 and reset, just like the analog clock.

The display shows minutes : seconds. During a set the minutes digit stays at 00.
00:00 = the top — most common push-off point.
00:30 = the bottom — used for alternating starts.
When you touch the wall, read the number instantly — that is your split time.
Some digital clocks show a second timer running 30 seconds behind, like a two-hand analog clock.

Parent Tip

If your child's pool has a digital clock, everything in this guide applies exactly the same way — just read the number on the display instead of looking at a hand position.

3. How to Use the Pace Clock at Practice

Starting on the Top (Most Common)

When your coach says "Go on the top", push off the wall the moment the hand reaches 60 (12 o'clock).

Watch the sweep hand approach the top of the clock.
As it hits 60/0, push off and start swimming.
When you touch the wall, glance at the clock — that number is your split time.
Rest until your next start time, then go again.

Starting on the Bottom (30-Second Starts)

"Go on the bottom" means push off when the hand hits 30 (6 o'clock). This lets two swimmers alternate — one starts at :00, the other at :30.

Understanding Intervals

An interval is the total time for one swim plus rest.

Example

"4 × 50 on 1:00" — swim 50 meters 4 times. Each swim plus rest must fit within 60 seconds.

How to figure out your rest:

Push off at :00 (the top).
Touch the wall — the clock reads :42. Your swim took 42 seconds.
Rest = 1:00 − 0:42 = 18 seconds.
Push off again on the next :00.

Swimmer Tip

Glance at the clock the instant you touch the wall. Don't look away for long — you need to know when to push off next!

4. Two-Hand Pace Clocks

Some pace clocks have two hands — one red and one green (or white) — running 30 seconds apart.

The red hand is typically for swimmers starting on the top (:00).
The green hand is for swimmers starting on the bottom (:30).
Your coach will tell you which hand is yours.
Swimmers can see their own start time without doing extra mental math.

5. Sample Scenarios

These examples walk through what a swimmer sees and does during a real practice set.

Scenario A — 4 × 50 on 1:30 (One-Minute-Thirty)

Coach says: "Four fifties on a 1:30, leaving on the top."

Clock hits :00 — push off and swim your 50.
Touch the wall. Clock reads :48. Split = 48 seconds.
Rest = 1:30 − 0:48 = 42 seconds. Stay at the wall and breathe.
The hand passes :00 and reaches :30 — that's your next start.
Push off on :30 and repeat. Start pattern: :00 → :30 → :00 → :30.

Reading the Clock

On a 1:30 interval you always push off 30 seconds past the top, alternating :00 and :30 each repeat.

Scenario B — 4 × 50 on 1:45 (One-Minute-Forty-Five)

Coach says: "Four fifties on a 1:45, leaving on the top."

Clock hits :00 — push off and swim your 50.
Touch the wall. Clock reads :52. Split = 52 seconds.
Rest = 1:45 − 0:52 = 53 seconds.
Next start lands on :45 of the same revolution.
Push off on :45. Start pattern: :00 → :45 → :30 → :15.

Swimmer Tip

On a 1:45, your start shifts back 15 seconds each repeat. After 4 repeats the cycle returns to :00.

Scenario C — Faster Swimmer on the Same 1:30 Set

Push off at :00. Touch the wall at :38. Split = 38 seconds.
Rest = 1:30 − 0:38 = 52 seconds. More rest as you get faster!
Next push-off is still :30 — the interval never changes.

Key Point

The interval never changes — only your rest does. Swim faster = more rest. Swim slower = less rest.

6. Quick Reference Glossary

Term	What It Means
Pace Clock	The large clock at the pool end used to time swims and starts.
Split	Your time for one swim — read off the clock when you touch the wall.
Interval	Total time for one swim plus rest (e.g., 1:00 = swim + rest within 60 seconds).
Rest	Time between touching the wall and your next push-off. Rest = Interval − Split.
Top	The 12 o'clock position (:00 / :60). Most common start position.
Bottom	The 6 o'clock position (:30). Used for alternating-start sets.
On the top	Coach instruction: push off when the hand hits :00.
On the bottom	Coach instruction: push off when the hand hits :30.
Set	A group of swims with the same instructions (e.g., 4 × 50 on 1:00).
Repeat	One single swim within a set. Four repeats = four swims.

7. Swimming Pace Chart

Use this chart to estimate how long a longer swim should take based on your 100-meter pace. Find your comfortable 100 time in the first column, then read across for projected times at other distances.

Example: If you swim 100 meters in 1:45, you should be able to swim 500 meters in about 8:45. For interval training, add 10–15 seconds to your 100 pace to set a comfortable repeat interval.

100	200	300	400	500	600	800	1000	1500	1-Hour
1:00	2:00	3:00	4:00	5:00	6:00	8:00	10:00	15:00	6,000
1:05	2:10	3:15	4:20	5:25	6:30	8:40	10:50	16:15	5,535
1:10	2:20	3:30	4:40	5:50	7:00	9:20	11:40	17:30	5,140
1:15	2:30	3:45	5:00	6:15	7:30	10:00	12:30	18:45	4,800
1:20	2:40	4:00	5:20	6:40	8:00	10:40	13:20	20:00	4,500
1:25	2:50	4:15	5:40	7:05	8:30	11:20	14:10	21:15	4,235
1:30	3:00	4:30	6:00	7:30	9:00	12:00	15:00	22:30	4,000
1:35	3:10	4:45	6:20	7:55	9:30	12:40	15:50	23:45	3,785
1:40	3:20	5:00	6:40	8:20	10:00	13:20	16:40	25:00	3,600
1:45	3:30	5:15	7:00	8:45	10:30	14:00	17:30	26:15	3,425
1:50	3:40	5:30	7:20	9:10	11:00	14:40	18:20	27:30	3,270
1:55	3:50	5:45	7:40	9:35	11:30	15:20	19:10	28:45	3,130
2:00	4:00	6:00	8:00	10:00	12:00	16:00	20:00	30:00	3,000
2:05	4:10	6:15	8:20	10:25	12:30	16:40	20:50	31:15	2,880
2:10	4:20	6:30	8:40	10:50	13:00	17:20	21:40	32:30	2,765
2:15	4:30	6:45	9:00	11:15	13:30	18:00	22:30	33:45	2,665
2:20	4:40	7:00	9:20	11:40	14:00	18:40	23:20	35:00	2,570
2:30	5:00	7:30	10:00	12:30	15:00	20:00	25:00	37:30	2,400
2:40	5:20	8:00	10:40	13:20	16:00	21:20	26:40	40:00	2,250
2:50	5:40	8:30	11:20	14:10	17:00	22:40	28:20	42:30	2,115
3:00	6:00	9:00	12:00	15:00	18:00	24:00	30:00	45:00	2,000

How to Use This Chart for Intervals

Find your comfortable 100 pace, then add 10–15 seconds to set a good repeat interval. If your 100 pace is 1:45, a comfortable interval would be 1:55 or 2:00 — giving you just enough rest to catch your breath before the next repeat.

Source: U.S. Masters Swimming — Swimming Pace Chart