How Many Calories Does F45 Burn?

F45 calories by weight & duration

The roughly 598 calories per hour figure is a MET-based estimate for someone around 155 lbs working consistently through the session, and your actual number will be higher or lower depending on your weight, fitness level, and how hard you push at each station. Log your F45 sessions in the Mariposas app to track burn over time and see how your output changes as you get fitter.

Calculated as MET (8.5) × body weight (kg) × hours. How this works.

What to expect in a f45 class

Walk in and you'll find numbered stations set up around the room, each marked with a card or screen showing the movement and the rep target or time domain. A central display counts down your work interval and rest period, so you move from station to station on cue rather than self-directing. Depending on the day's format, you might spend 35 seconds on a kettlebell swing, rotate to battle ropes, then hit a box step-up, all in quick succession with brief transitions in between. The first session often feels more disorienting logistically than physically, since you're reading movements and figuring out equipment while also trying to work hard.

Tips for your first f45 class

• Arrive five to ten minutes early on your first visit and tell the coach it's your first class. They can walk you through the station layout and flag which movements have easier entry-point modifications, which saves you from stalling mid-circuit trying to figure out a new exercise.
• Read the station card before your work interval starts. You get a rest window between sets, and that's the moment to glance at the next card and mentally rehearse the movement so you're not burning your first few seconds decoding instructions.
• Scale aggressively at first. A goblet squat at a weight where you can hold solid form for the full interval will do more for you than grinding through a heavier load with compensated mechanics, especially when fatigue stacks across ten or twelve stations.
• Bring water and expect the room to get warm. Because the format keeps rest periods short and structured, there's no natural pause where everyone stops for a long break. A small water bottle you can grab between stations without slowing your rotation is the practical move.

What affects how many calories f45 burns

The 598 cal/hr estimate applies to a 155 lb person working at genuine effort through the full session, and it scales upward with body weight and downward if you're lighter or taking longer rest breaks than the timer allows. On resistance-heavy days the calorie burn during the workout may feel lower than on pure cardio days, but the post-session metabolic demand from muscle repair adds a component that the MET figure alone doesn't fully capture. Short rest periods and compound movements like deadlifts, thrusters, or burpees are what keep intensity high, so how hard you push during each work window is the biggest variable within your control.

Three things move your number most: body weight (a heavier body burns more for the same activity, that's why the table runs from 125 to 225 lb), duration (calories scale with time), and intensity. A f45 you push hard burns more than an easy one, because effort is what the MET value of 8.5 represents, an average for this activity. Your fitness level and how much you rest between efforts shift it too, so treat these as a solid estimate rather than an exact count.

How we calculate f45 calories

Every number here uses the standard energy-expenditure formula: calories ≈ MET × body weight (kg) × time (hours). The MET value of 8.5 for f45 comes from the published Compendium of Physical Activities, the same reference researchers and fitness trackers use. We convert your weight to kilograms and multiply through, no fudge factors. See our methodology for the full formula and sources.