Strength and heart-rate zone calculators

Two training estimates: a one-rep max from a set of 1 to 12 reps (Epley), and five pulse zones from age and resting HR (Karvonen, max HR = 220 − age). Neither is a lab test.

Epley sets 1RM = load × (1 + reps/30). Beyond 10 reps the extrapolation drifts. Karvonen targets a share of reserve (max − rest), not a share of raw max HR. Beta blockers, lifting technique and a real effort test sit outside the model.

Most used

One-rep max (Epley)A load and a rep count (1 to 12). The tool applies Epley, not a true single-attempt max.
Heart-rate zonesAge and resting pulse. The tool estimates max HR (220 − age) and five zones on the reserve.

Subcategories

Strength

1RM estimated with Epley’s formula, 1 to 12 reps.

One-rep max (Epley)

Cardio

Five Karvonen zones from 220 − age and resting pulse.

Heart-rate zones

Full list

Questions

Can I load the bar to the estimated 1RM?

It is an estimate, not a max-attempt instruction. Beyond about 10 reps, change protocol. A spotter and stable technique still beat the number.

Why 220 minus age, not Tanaka?

Because 220 − age is the most common request. True max HR is tested individually. Tanaka (208 − 0.7×age) exists; this page stays on Fox–Haskell and says so.