12 % incline · 3 mph · 30 min

12-3-30 Calories Burned at 300 lb

A 300 lb (136 kg) person burns about 590 calories doing the 12-3-30 treadmill workout — roughly 2.5× as many as 30 minutes of flat walking.

12-3-30 (gross)
590
kcal in 30 min
Net (above rest)
519
kcal
Flat 3 mph walk
236
kcal in 30 min
Per hour at 12 %
1181
kcal

Use your own numbers: open the 12-3-30 calories calculator →

30-minute calories at 300 lb by incline and speed

Incline2.5 mph3.0 mph3.5 mph4.0 mph
0 %208236263290
3 %282324367409
6 %356413470527
9 %430502573645
12 %504590677763
15 %578679780882

ACSM walking equation: VO2 = 0.1·S + 1.8·S·G + 3.5 (S in m/min, G as a fraction); kcal ≈ VO2 × kg ÷ 1000 × 5 per minute. Valid for walking speeds of roughly 1.9–3.7 mph; values at 4.0 mph are an extrapolation.

Is 12-3-30 a good workout?

It is a demanding but low-impact cardio session: at 12 % incline the energy cost of walking at 3 mph is similar to running at roughly 4.5–5 mph on the flat. Steep incline walking loads the calves and Achilles, so build up the incline and duration gradually and avoid holding the handrails, which reduces the work.

Other body weights

Try any speed and incline with the incline walking calculator, or compare with a treadmill running session.

Last reviewed: October 2026 · Health disclaimer

FAQ

12-3-30 at 300 lb: questions

About 590 kcal in 30 minutes (gross) for a 300 lb (136 kg) person, using the ACSM walking equation at 12 % incline and 3 mph. That is about 519 kcal above resting.

Walking 30 minutes at 3 mph on the flat burns about 236 kcal at 300 lb, so the 12 % incline roughly 2.5× the energy cost.