MAF Heart Rate Calculator (Maffetone 180 Formula)
Find your MAF heart rate with Phil Maffetone’s 180 formula: 180 minus your age, adjusted for your health and training history, plus your aerobic training zone in bpm.
How it works
MAF heart rate = 180 − age + adjustment (−10, −5, 0 or +5 by health and training profile; athletes aged 16 or under use 165 bpm) · aerobic zone = MAF − 10 to MAF
The Maximum Aerobic Function (MAF) method, developed by Dr Phil Maffetone, sets a heart-rate ceiling for base training so that most work is done aerobically. Start from 180, subtract your age, then adjust: −10 if you are recovering from a major illness or take regular medication, −5 if you are injured, regressing, often ill or train inconsistently, 0 if you have trained consistently for up to two years, and +5 if you have trained for more than two years and are still improving. Train at or a little below the number, and re-test pace at that heart rate every few weeks.
Worked example
A 40-year-old who has trained consistently for a year without injury: MAF = 180 − 40 + 0 = 140 bpm, so easy aerobic sessions stay between 130 and 140 bpm.
Sources: Maffetone P — The MAF 180 Formula: heart-rate monitoring for real aerobic training · Maffetone P, Laursen PB (2016) Athletes: fit but unhealthy? Sports Med Open 2:24
Frequently asked questions
What is the MAF 180 formula?
It is Phil Maffetone’s rule of thumb for the top of your aerobic zone: 180 minus your age, then adjusted by −10, −5, 0 or +5 depending on your health and training history. It is not derived from a lab test, but it gives a conservative ceiling that keeps easy runs truly easy.
Why does MAF training feel so slow?
Most recreational runners do their easy runs too fast. Staying under the MAF heart rate often means walking hills at first; as the aerobic system improves, the pace you can hold at the same heart rate gets faster — that improvement is the goal of the method.
Is the MAF heart rate the same as zone 2?
They are similar but not identical. Zone 2 is usually defined as a percentage of maximum or reserve heart rate, or from lactate testing, while MAF uses only age and history. For many people the MAF number lands near the top of zone 2.
What if I am 16 or younger, or over 65?
Maffetone suggests that athletes aged 16 or under use 165 bpm rather than the formula. Older athletes may need individual adjustment — some well-trained over-65s add up to 10 bpm — which is best decided with a coach or by testing.
Related calculators
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.