HIIT Calories Burned Calculator

Calories burned in HIIT (high intensity interval training) is the energy your body uses during a workout of short, hard efforts split by short rests, counted in kilocalories (kcal). It is estimated from three things: your body weight, your workout time and the kind of HIIT you do. Every HIIT type has a MET value, which shows how hard an activity is compared with sitting still.

What the Estimate Measures

It shows the total energy your workout uses, with the energy your body would burn at rest anyway left in (a gross value). It does not include the small extra burn after you stop, and it is an average for adults, not a reading of your own fitness.

The Formula

Calories (kcal) = MET x body weight (kg) x time (hours)

Body weight (kg) = body weight (lb) x 0.45359237

One MET is about 1 kcal per kg of body weight per hour, and the MET values come from the 2024 Adult Compendium of Physical Activities, which has its own rows for interval exercise¹.

How This Calculator Computes Your Result

Enter your weight in pounds or kilograms, your age group and a HIIT type, then either your whole workout time or your intervals (work time, rest time, rounds, sets and the break between sets). Results are given to the nearest 5 kcal. The tool also lists calories per hour and per 30 minutes, plus a table of each HIIT type at your weight.

HIIT has no value for adults 60 and over in the compendium, so from 60 you see the adult result with a note that values may be lower. Children and teens under 18 see no HIIT result, because their values differ (see the Youth Compendium).

What Your Result Means

The HIIT type you choose makes the biggest difference to your result. At 70 kg (154 lb), each HIIT option gives these figures.

Vigorous bodyweight HIIT has one of the higher values in the compendium, but HIIT workouts are often short, so the total is usually a few hundred kcal¹. Calories rise in step with body weight.

How Work and Rest Intervals Are Counted

The compendium gives one value for each kind of interval workout, with no separate value for the work bursts or the rests, and it does not state a work to rest ratio¹. The vigorous row names Tabata, a format built on 20 seconds of work and 10 seconds of rest, so short rests are part of what the row describes¹.

So in Intervals mode, the calculator counts your work time plus the short rests between intervals at the row's value. It does not invent a separate value for rest. Breaks between sets are shown but not counted, and the result is labeled active time only. For example, four Tabata sets of 8 rounds with 1 minute between sets count as about 15.3 minutes of an 18.3 minute session. If your rests are more than twice as long as your work, such as 30 second bike sprints with 4 minutes of easy pedalling, you will see a note that the estimate may be high.

What a Tabata Workout Really Burns

The name comes from a 1996 lab study on exercise bikes: 7 to 8 bouts of 20 seconds at about 170% of VO2max (a workload 1.7 times the one that draws out your maximum oxygen uptake), each followed by 10 seconds of rest². Over 6 weeks it raised both aerobic fitness and anaerobic capacity².

A 2013 study of a bodyweight Tabata workout is closer to a typical class. Sixteen trained adults did four 4-minute blocks of as many reps as possible in 20 seconds, then 10 seconds of rest, with 1 minute between blocks³. Heart rate averaged 86% of maximum, estimated oxygen use averaged about 35 mL per kg per minute (roughly 10 METs), and the workout burned an estimated 240 to 360 kcal³. That is close to the compendium's vigorous HIIT value of 11.0 METs¹.

The Afterburn Effect Is Real but Small

HIIT is often sold on its afterburn, the extra oxygen your body uses after hard exercise (excess post-exercise oxygen consumption, or EPOC). A major review found that a long afterburn (3 to 24 hours) follows only hard enough exercise, and even then it equals about 6 to 15% of the net oxygen cost of the exercise itself⁴. The authors judged its role in weight loss to be overstated⁴.

A 2021 review of 22 studies found more afterburn after interval exercise than after steady moderate exercise⁵. Measured up to 3 hours afterward, it averaged about 136 kJ (33 kcal) after HIIT against 101 kJ (24 kcal); measured for longer, about 289 kJ (69 kcal) against 159 kJ (38 kcal)⁵. So choosing HIIT adds roughly 8 to 31 kcal of afterburn. This calculator does not add it.

HIIT Compared With CrossFit-Style Circuits, Spin Class, Running and Jump Rope

For two body weights, the table below shows 60 minutes of each activity, based on 2024 compendium values¹.

The compendium has no CrossFit row, so the closest match is vigorous circuit training with kettlebells and minimal rest¹. Per minute, vigorous HIIT is close to moderate jump rope and above running at a 10-minute mile, while moderate HIIT sits below a spin class. Because HIIT sessions are usually short, a longer run or spin class can burn more in total.