To see in numbers whether you’re working hard enough, check your heart rate. The American Heart Association (AHA) puts maximum heart rate at about “220 minus your age”, with moderate exercise at 50 to 70% of that and vigorous at 70 to 85%. At 40 that’s a maximum of 180, moderate 90 to 126 and vigorous 126 to 153. Enter your age below for your ranges. This sets out the AHA’s “Target Heart Rates Chart”.
1. Maximum heart rate ≈ 220 minus your age. The AHA calls it “about”.
2. Moderate 50–70%, vigorous 70–85%. At 40: moderate 90–126, vigorous 126–153.
3. Count your pulse for 30 seconds and multiply by 2. With a heart condition or medication, ask a health professional for your target.
Updates as you type. Maximum heart rate is the AHA estimate “220 minus your age”; ranges use the AHA’s 50–70% moderate and 70–85% vigorous, rounded. The 30-second row reverses the AHA’s “count for 30 seconds and multiply by 2” (our working). If you have a heart condition or take medication, ask a health professional for your target.
The AHA table by age
The AHA’s table by age. Every figure equals 220 minus age times 50% and 85%, rounded (we recalculated each to check).
| Age | Target zone (50–85%) | Estimated maximum |
|---|---|---|
| 20 | 100–170 bpm | 200 bpm |
| 30 | 95–162 bpm | 190 bpm |
| 35 | 93–157 bpm | 185 bpm |
| 40 | 90–153 bpm | 180 bpm |
| 45 | 88–149 bpm | 175 bpm |
| 50 | 85–145 bpm | 170 bpm |
| 55 | 83–140 bpm | 165 bpm |
| 60 | 80–136 bpm | 160 bpm |
| 65 | 78–132 bpm | 155 bpm |
| 70 | 75–128 bpm | 150 bpm |
The AHA notes some medicines can lower your maximum heart rate and target zone, so these ranges may not fit.
Taking your pulse and resting heart rate — AHA
| Type | What the source says | Worth noting (ours) |
|---|---|---|
| Pulse | Count for 30 seconds and multiply by 2 | The calculator’s 30-second row reverses this (our working) |
| Resting | For most adults 60–100 bpm is normal | — |
| Medication or heart condition | Ask a health professional for your target | — |
Where moderate and vigorous come in
Activity guidelines (150 minutes of moderate activity a week and so on) also judge intensity by breathlessness. The talk test is in exercise intensity talk test, and weekly amounts in brisk walking. Heart rate and the talk test read the same thing on different scales (our gloss).
Checklist
- ☐ Enter your age for maximum heart rate (220 minus age)
- ☐ Moderate 50–70%, vigorous 70–85%
- ☐ During exercise, count for 30 seconds and double it
- ☐ On medication or with a heart condition, ask a professional
Questions that remain
Is 220 minus age accurate?
The AHA itself says “about”. It’s an estimate that varies between people and can be lowered by some medicines.
Which age do I use?
The AHA table uses age in completed years, which is also Korea’s legal age (our gloss).
Sources
- American Heart Association (AHA) — Target Heart Rates Chart — source (page shows: last reviewed 12 August 2024; checked 19 October 2026). 220 minus age, moderate 50–70%, vigorous 70–85%, resting 60–100, 30 seconds × 2, the 10-row age table (all recalculated to match), medication caution.
- Not read. Korean agency guidance on target heart rate.
- What we added. The “worth noting” column and the Korean everyday gloss.
Where else to check
- Your health professional — if you take medication or have a heart condition.
Written on 19 October 2026. The content is from the source; the glosses are ours.
