What this result means
Coaches write rest as a ratio of the work interval. This calculator multiplies. The interval workout page wants seconds; start here if you only know 1:1.
Heart-rate zones are a different language on the heart category. A 1:1 jog can still be too fast if you sprint the work.
2:00 work at 1:1 is 2:00 rest. 90 seconds work at 1:2 is 3:00 rest. 45 seconds at 1:0.5 is 22–23 seconds rest, rounded to the nearest second.
Cruise intervals often use short rest (1:0.5). VO2 400s often use 1:1 to 1:2. The tool does not pick for you.
Calculation method
Rest = work seconds × ratio. 1:2 means ratio 2. Displayed times round to the nearest second.
Exact arithmetic.
Ratios ignore that the last rep has no rest. They also ignore that a 400 m in 70 s and a 400 m in 90 s are different workouts at the same ratio.
Frequently asked questions
What is 1:1 recovery?
Rest equals work. A 60-second rep gets 60 seconds rest.
What is 1:2?
Rest is twice the work. A 60-second rep gets 120 seconds rest.
Does this set my heart-rate zone?
No. It only multiplies times. Use the heart-rate calculator for zones.