Body Measurements
Track your weight and tape measurements over time — the honest, operator-proof way to watch your body change.
Powerhaus stores your bodyweight, your girths (neck, waist, hips, chest, arms, thighs, calves), and — if you want — a body-fat percentage you enter yourself, then charts any of them over time. We deliberately don’t guess your body fat from a formula: a tape measurement you trend week to week is a cleaner, more reliable signal than a point-in-time estimate that stacks its own error on top of the tape’s.
See it in the app
Open the Analytics tab
Scroll to Body Measurements and tap the card to open the chart
Tap + to log a new set of measurements
Use the metric selector to switch between Weight, Body Fat %, and each girth
Even this is in Bronze — the whole tracker is $1/mo, and nothing here is locked behind a higher tier.
Why it matters
The scale alone lies to lifters — bodyweight can sit flat while your waist shrinks and your arms grow. Tracking individual girths separates “the number didn’t move” from “nothing changed,” which is often the difference between quitting and staying the course.
A tape and a scale are the two most accessible body tools there are. Logging them consistently turns vague “I think I’m leaning out” into an actual line you can read — no lab, no calipers, no guesswork.
How Powerhaus calculates it
There’s no calculation to hide — we store exactly what you measure and plot it. Pick a metric (Weight, Body Fat %, or any single girth) and the chart draws it across your chosen time range.
Body Fat % is a number you type, validated to a sane 1–60% range. We keep it because many lifters get it from a DEXA scan or a caliper reading and want it trended alongside everything else — but we never compute or overwrite it.
Everything is stored raw in your chosen unit, so a girth is just that girth over time — the truest form of the data.
The science
Raw girth tracking is the quiet winner, and the measurement literature backs it. Tape circumferences are comparatively operator-independent — reliable to a few percent even between different measurers (EXERNET reliability study) — whereas any body-fat estimate compounds the tape’s error with the formula’s. Trending one honest number beats trending a shakier derived one.
Waist, specifically, is a meaningful marker on its own. WHO waist thresholds and the waist-to-height ratio are standardized, near-sex-agnostic health signals (WHO waist cutoffs; waist-to-height ratio) — so your waist line is doing real work, not just vanity tracking.
Why we don’t auto-compute body fat (the honest version). The popular tape-based estimate (the U.S. Navy method) is decent — about 3.5% standard error versus a dunk tank (NCBI, Body Composition in the Military) — but it’s biased in known ways: it reads men low and women high versus a DEXA scan, and it’s worst at the very lean and very heavy ends (Marine Corps DEXA study). It also needs your height and sex, which we don’t currently store. Rather than ship a biased estimate dressed up as a verdict, we keep the raw trend.