ACSM Metabolic Equations Calculator
Calculate oxygen uptake (VO2), METs and calories with the ACSM metabolic equations for walking, running, leg and arm cycle ergometry and bench stepping.
How it works
S = speed (m/min), G = grade (decimal), WR = work rate (kg·m/min = W × 6.12), BM = body mass (kg), f = steps/min, H = bench height (m) · Walking: 0.1S + 1.8SG + 3.5 · Running: 0.2S + 0.9SG + 3.5 · Leg cycling: 1.8WR/BM + 7 · Arm cycling: 3WR/BM + 3.5 · Stepping: 0.2f + 1.33 × 1.8Hf + 3.5 (ml/kg/min) · kcal/min = VO2 × BM ÷ 1000 × 5
The American College of Sports Medicine metabolic equations estimate steady-state oxygen cost from the external workload: a horizontal component, a vertical (or resistance) component and a resting component of 3.5 ml/kg/min. They are used in exercise physiology courses, the ACSM certification exams and for prescribing treadmill, bike or step workloads. Each equation is valid only for steady-state, submaximal exercise in its stated range — walking 50–100 m/min, running above 134 m/min, leg cycling 50–200 W and arm cycling 25–125 W.
Worked example
A 70 kg person walks at 5.6 km/h (93.3 m/min) up a 5% grade for 30 min: VO2 = 0.1 × 93.3 + 1.8 × 93.3 × 0.05 + 3.5 = 9.33 + 8.4 + 3.5 = 21.2 ml/kg/min (6.1 METs). Absolute VO2 = 21.23 × 70 ÷ 1000 = 1.49 L/min, so energy = 7.4 kcal/min and 223 kcal in 30 min.
Frequently asked questions
What are the ACSM metabolic equations?
They are five regression equations published in ACSM’s Guidelines for Exercise Testing and Prescription that convert a workload — speed and grade, watts or stepping rate and height — into oxygen consumption. From VO2 you can get METs and calories.
Why does leg cycling add 7 instead of 3.5?
The leg-ergometer equation includes 3.5 ml/kg/min for rest plus another 3.5 ml/kg/min for the cost of moving the legs against zero resistance (unloaded pedalling).
Can I use the walking equation for jogging at 7 km/h?
Speeds between about 100 and 134 m/min (6–8 km/h) are a grey zone. If you are actually jogging, the running equation is more accurate; if you are walking fast, the walking equation tends to underestimate.
How accurate are the calories?
The equations predict the average oxygen cost within about 7% for most people in steady state. Calories use 5 kcal per litre of oxygen, which is typical for a mixed diet; the real value ranges from 4.7 to 5.05.
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This calculator gives an estimate for general fitness and education only. It is not medical advice — prediction equations can differ from measured values, so talk to a doctor or qualified exercise professional before changing your training, especially if you have a heart condition or take medication.