What is my body fat percentage? Five ways to find out at home
From a free chart to AI: how each method works, how accurate it is, and which to use for tracking.
Short answer
The easiest accurate home method is a tape measure: neck, waist (and hips for women) plus height in the US Navy formula, within about 3–4 points. Comparing with a body fat photo chart is quicker but rougher. AI photo estimates vary with lighting; combining photos with tape measurements, as ProgressLens does, gives a steadier range.
Five ways, compared
| Method | Typical error | Cost | Best for |
|---|---|---|---|
| Compare with a photo chart | 5+ points | Free | A first guess |
| Tape measure (US Navy) | About 3–4 points | Free | Repeatable tracking |
| Smart scale (BIA) | 3–5 points, swings with water | $30–150 | Trends, same conditions |
| AI photo estimate | Several points, swings with light | Free–subscription | A quick read |
| Photos + tape + history (ProgressLens) | A range, steady between check-ins | Subscription | Tracking change |
1. Compare with a chart
Find the level that looks most like you in the body fat chart (men and women, 6% to 45%). Be honest about lighting: gym mirrors flatter.
2. Use a tape measure
Measure your neck below the larynx and your waist at the navel (women add hips at the widest point), then enter them with your height in the body fat calculator. Read how to measure body fat with a tape measure.
3. Ask an AI
ChatGPT and AI apps can estimate from a photo, but different chats give different numbers. Use a careful prompt (see the ChatGPT body fat prompt) and treat the answer as a range.
4. Track it, don’t just measure it once
Body fat changes slowly, so the trend matters more than any reading. Same method, same conditions, every two to four weeks, beside matched photos.
FAQ
Frequently asked questions
How can I tell my body fat percentage without calipers?
Use a tape measure and the US Navy formula, or compare with a body fat photo chart.
Can I find my body fat percentage from a picture?
Roughly. A photo gives a first guess within several points; adding tape measurements makes it steadier.
Is there an app that tells you your body fat percentage?
Yes. See apps that measure body fat.