A1C converter
An A1C of 7% matches an estimated average glucose of 154.2 mg/dL under the ADA formula. Convert either way to understand a lab report or a lesson, then discuss your own results with a qualified health professional. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
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Worked example
- Convert
- A1C to average glucose
- A1C (%)
- 7
- Estimated average glucose (mg/dL)
- 154.2
Educational tool, not a diagnosis or medical advice — do not use it for treatment decisions. Discuss personal results with a qualified health professional.
What A1C and estimated average glucose describe
A1C is a blood test reported as a percentage. It reflects roughly the last three months of blood sugar, because glucose attaches to red blood cells over their lifespan. Estimated average glucose, or eAG, expresses that same picture in mg/dL, the unit many people see on a home meter. The American Diabetes Association links the two with a straight-line formula: multiply A1C by 28.7 and subtract 46.7. An A1C of 7% therefore corresponds to about 154.2 mg/dL, the familiar figure clinicians quote. The converter also works in reverse, turning an average glucose into the matching A1C.
Why your own numbers can differ
The formula comes from studies of many people, so it describes an average relationship, not your personal one. Red blood cell turnover, anemia, pregnancy and some hemoglobin variants can make an individual's meter readings drift away from the estimate. The tool only accepts plausible values, an A1C from 3 to 20% or an average glucose from 40 to 600 mg/dL, and rounds the result once, to one decimal by default for glucose and two for A1C. Use it to learn and to prepare questions, not to change treatment; if you have symptoms or a worrying number, contact a health professional, and seek emergency care for urgent symptoms.
The ADA A1C to eAG formula
Every response also carries method: 'ada' so downstream systems can record which regression produced the number. For example, an A1C of 7 converts to an eAG of 154.2 mg/dL at the default one-decimal rounding — the familiar '7% is about 154' figure clinicians cite. The relationship is a population-level average derived from continuous-glucose-monitoring studies, so an individual's true average glucose can differ from this estimate.
Interpretation, safety and determinism
Clinically, eAG smooths roughly three months of blood glucose into a single average and can diverge from an individual's meter readings because of red-blood-cell turnover, anemia, pregnancy or hemoglobin variants. Anyone with symptoms or a concerning number should contact a qualified health professional, and urgent symptoms warrant local emergency care rather than a calculator.
FAQ
Is this a diagnosis or medical advice?
No. It is an educational conversion based on the ADA formula; it cannot diagnose a condition or replace care from a qualified health professional.
Can I make treatment decisions from this result?
No. Do not start, stop or change treatment from this estimate. Discuss personal results and decisions with a qualified health professional.
Why can this differ from a clinical result?
eAG is a population-based average; an individual's glucose can differ because of red-blood-cell turnover, anemia, pregnancy or hemoglobin variants, and needs professional interpretation in context.
What if I have symptoms or am worried about a result?
Contact an appropriate qualified health professional. For urgent symptoms or an emergency, seek local urgent or emergency care.
What is the formula from A1C to average glucose?
Multiply the A1C percentage by 28.7 and subtract 46.7 to get the estimated average glucose in mg/dL. For an A1C of 7%, that is 154.2. To go back, add 46.7 and divide by 28.7.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/dev/a1c-converter \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"mode":"a1c_to_eag","a1c":7}'const res = await fetch("https://api.kit.forhosting.com/dev/a1c-converter", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"mode": "a1c_to_eag",
"a1c": 7
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/dev/a1c-converter",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"mode": "a1c_to_eag",
"a1c": 7
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/dev/a1c-converter", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"mode":"a1c_to_eag","a1c":7}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"mode":"a1c_to_eag","a1c":7}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/dev/a1c-converter", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"mode": "a1c_to_eag",
"a1c": 7
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "dev.a1c_converter",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Converts an A1C percentage to estimated average glucose (eAG) in mg/dL using the ADA linear formula eAG = 28.7 × A1C − 46.7, or eAG back to A1C. API from $0.002.
The ADA A1C to eAG formula
This converter implements the American Diabetes Association's linear relationship between hemoglobin A1C and estimated average glucose (eAG): eAG in mg/dL = 28.7 × A1C − 46.7, and its algebraic inverse A1C = (eAG + 46.7) / 28.7. The mode field selects the direction: 'a1c_to_eag' reads the a1c field and returns eag_mg_dl, while 'eag_to_a1c' reads the eag field and returns a1c.
Inputs, ranges, rounding and validation
Inputs are range-checked to keep values physiologically plausible before any arithmetic. The decimals field itself must be an integer from 0 to 2. In 'a1c_to_eag' mode the a1c field must be a finite number between 3 and 20 percent, and decimals defaults to 1; in 'eag_to_a1c' mode the eag field must be between 40 and 600 mg/dL, and decimals defaults to 2. An unrecognised mode, an out-of-range measurement, or a bad decimals value each return a typed invalid_input error — 'a1c inválido', 'eag inválido', 'mode inválido' or 'decimals fuera de rango' — so a form can highlight the exact field. The single converted value is rounded once with an explicit half-up rule on the raw computed number, and the input you supplied is echoed back unrounded alongside it, making the JSON response self-documenting for logs and pipelines.
Integration use cases
Patient-facing conversion widget
Embed the tier-A browser widget so readers can turn an A1C percentage into an estimated average glucose in mg/dL, with the not-medical-advice notice attached.
Health-app data pipelines
Call the API in 'eag_to_a1c' mode to normalise glucose figures back to A1C for storage, using method:'ada' to record the conversion basis.
Reproducible fixtures
Use the deterministic ADA formula as a stable test vector — A1C 7 to eAG 154.2 — in automated checks that must not drift over time.
Technical questions
What formula and ranges does it use?
eAG in mg/dL = 28.7 × A1C − 46.7, and its inverse. A1C is accepted from 3 to 20 percent and eAG from 40 to 600 mg/dL; values outside those ranges return invalid_input.