Add up your week
The honest arithmetic: moderate minutes plus twice your vigorous minutes, against the 150-minute baseline and 300-minute stretch goal. You classify the minutes; this counts them.
Public-health guidance treats 75 vigorous minutes as roughly 150 moderate minutes — that is the 2-to-1 rule. The app can classify minutes from your live heart rate; on the web you enter them yourself.
This calculator is intentionally simple.
It asks for:
- moderate minutes
- vigorous minutes
Then it calculates:
moderate-equivalent minutes = moderate + 2 x vigorousWhy The Formula Is Simple
Public-health guidance often treats 75 minutes of vigorous aerobic activity as comparable to 150 minutes of moderate aerobic activity.
That creates the 2-to-1 rule.
Examples:
| Moderate | Vigorous | Score |
|---|---|---|
| 150 | 0 | 150 |
| 90 | 30 | 150 |
| 60 | 45 | 150 |
| 0 | 75 | 150 |
All four hit the baseline.
Targets
Zonas compares the score against two targets:
| Target | Meaning |
|---|---|
| 150 | Baseline weekly cardio goal |
| 300 | Optional stretch target |
The app can also use a custom target.
Why This Tool Does Not Use Zones
The iOS app has your heart rate samples. It can classify minutes from the stream.
The web calculator does not.
So it should not pretend to know whether a specific minute was moderate or vigorous. You enter those minutes yourself, and the calculator applies the equivalence rule.
How It Relates To Zonas
The app uses the same moderate-equivalent idea, but with more context.
When resting heart rate exists, the app can classify moderate and vigorous intensity with heart rate reserve cutpoints. When resting heart rate is missing, it falls back to percent of max heart rate cutpoints.
The web tool is just the final arithmetic.
That is enough for a quick check.
Common questions
Why does vigorous time count double?
Public-health guidance commonly treats 75 minutes of vigorous activity as equivalent to 150 minutes of moderate activity. The calculator expresses that as moderate + 2 x vigorous.
Does this calculator use my heart rate zones?
No. The web tool asks for minutes you already classify as moderate or vigorous. The iOS app can classify from heart rate samples during the week.
What goal should I compare against?
The default Zonas baseline is 150 moderate-equivalent minutes per week. The optional stretch target is 300.
Sources
- What Counts as Physical Activity for Adults
CDC explains the adult target of 150 minutes moderate, 75 minutes vigorous, or an equivalent combination.
- WHO Guidelines on Physical Activity and Sedentary Behaviour
WHO adult guidance includes 150-300 moderate minutes, 75-150 vigorous minutes, or an equivalent combination.
- Physical Activity Guidelines for Americans, 2nd edition
U.S. guidance frames weekly aerobic targets as moderate, vigorous, or equivalent combinations.