Transferrin saturation (TSAT) calculator
Work out your transferrin saturation — also called iron saturation or TSAT — from the two numbers on your iron panel: serum iron and TIBC (total iron-binding capacity). Enter both in the same unit and you'll get your saturation percentage instantly.
Your privacy: this calculator runs entirely in your browser — nothing you type is sent anywhere. It's the same on-device principle Quanome is built on.
Educational reference only — not medical advice. Transferrin saturation is read alongside ferritin and the rest of the iron panel; reference ranges vary by lab.
## What your TSAT value means
| Transferrin saturation | How it's usually read |
| --- | --- |
| Below 15% | **Low** — carriers nearly empty; a strong pointer to iron deficiency, especially with low ferritin |
| 15–20% | **Borderline-low** — read against ferritin |
| 20–45% | Within the typical range |
| 45–50% | **Borderline-high** — pair with ferritin to check for early iron overload |
| Above 50% | **High** — the usual first flag for iron overload / hereditary hemochromatosis; warrants review |
These bands are a rough orientation, not diagnostic thresholds — a TSAT means little without **ferritin** next to it. For the full explanation, see [what your transferrin saturation means](/blog/what-your-transferrin-saturation-means/).
## The formula
**TSAT = (serum iron ÷ TIBC) × 100**
Serum iron is how much iron is currently in your blood; TIBC reflects how much your transferrin *could* carry. Their ratio is the fraction of iron-carrying capacity that's actually in use. Because both are reported in the same unit (µg/dL in the US, µmol/L in most other countries), the percentage is the same either way — just keep both numbers in the same unit. If you need to convert other results between units, our [mmol/L ↔ mg/dL converter](/tools/mmol-mg-dl-converter/) covers glucose, cholesterol and more.
## The rest of your iron panel
TSAT is one of several iron markers, best read together:
- **Ferritin** — your iron stores. See [what your ferritin level means](/blog/what-your-ferritin-level-means/).
- **Transferrin saturation** — iron in transit (this number). See [the full TSAT guide](/blog/what-your-transferrin-saturation-means/).
- The classic patterns: **low TSAT + low ferritin = iron deficiency**; **high TSAT + high ferritin = iron overload**. For a plain-English range summary, see [transferrin saturation](/blood-test-results/transferrin-saturation/) and [serum iron](/blood-test-results/iron/) in our blood test results library.
## Track your iron panel over time — privately
A single TSAT is a snapshot; the value is in the **trend**. [Quanome](/) pulls your labs, Apple Health, and even your DNA into one private timeline on your device — parsed locally, never uploaded — with an AI coach that reads your iron panel in context.
Track your iron panel over time, privately
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