RBC indices calculator
A hemoglobin of 15 g/dL, a hematocrit of 45% and a red cell count of 5 give an MCV of 90 fL and an MCH of 30 pg, plus the MCHC. Enter the three values from a blood count to get all three indices. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Hemoglobin
- 15
- Hematocrit
- 45
- Rbc count
- 5
- Mcv
- 90
- Mch
- 30
- Mchc
- 33.3333333333
- Unit hemoglobin
- g/dL
Red blood cell indices summarize how large circulating erythrocytes are and how much hemoglobin they carry, using three derived numbers from a complete blood count: mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). Students, educators, and health-software teams compute those classic Wintrobe indices from hemoglobin in grams per decilitre, hematocrit as a percent, and red blood cell count in millions per microlitre, which is numerically the same as ×10^12 per litre.
What MCV, MCH and MCHC measure and which CBC inputs you need
Mean corpuscular volume is the average volume of a single red cell, reported in femtolitres. Mean corpuscular hemoglobin is the average mass of hemoglobin inside one red cell, reported in picograms. Mean corpuscular hemoglobin concentration is the average hemoglobin concentration inside the packed red-cell mass, reported in grams per decilitre—the same unit as whole-blood hemoglobin.
Together they are the Wintrobe red-cell indices taught in every hematology course and printed on almost every automated CBC. This product computes them from three required scalars that already use the conventional teaching units: hemoglobin in grams per decilitre, hematocrit as a percent such as forty-five for forty-five percent (not a zero-to-one packed-cell fraction), and red blood cell count in ×10^12 per litre, which is numerically identical to millions of cells per microlitre on most laboratory printouts.
The three identities are MCV equals hematocrit percent divided by RBC count times ten, MCH equals hemoglobin divided by RBC count times ten, and MCHC equals hemoglobin divided by hematocrit percent times one hundred. Practical bounds keep consumer and classroom inputs sane: hemoglobin from zero point zero one through forty grams per decilitre, hematocrit from zero point zero one through one hundred percent, and RBC count from zero point zero one through twenty ×10^12 per litre.
Those ceilings catch common unit mistakes such as hemoglobin sent in grams per litre or an unconverted cell count in cells per microlitre.
Classroom uses and practical limits
Call the free in-browser RBC indices calculator for classroom demos, nursing homework checks, hematology worksheets, and quick personal learning without reimplementing the three formulas in every spreadsheet. If your UI only collects whole numbers, send integers and the engine still accepts numeric strings. Authors shipping SDKs can map the three indices into colour chips or teaching thresholds you define yourself and show the formula string on an education card.
Keep expectations educational: this is a calculation and learning tool, not a diagnostic medical device, and people with symptoms, known anemia, bleeding, or medication changes should follow professional medical advice rather than any single automated red-cell index alone.
What you can do with it
Health education apps and worksheets
Apps show learners how Wintrobe indices are derived from a CBC trio without re-coding the three textbook formulas on every client.
FAQ
How are MCV, MCH, and MCHC calculated?
MCV (fL) = (hematocrit % / RBC ×10^12/L) × 10. MCH (pg) = (hemoglobin g/dL / RBC ×10^12/L) × 10. MCHC (g/dL) = (hemoglobin g/dL / hematocrit %) × 100. Send those three required positive fields; the response includes mcv, mch, mchc, and a readable formula string.
What happens if hemoglobin or the red blood cell count is zero or negative?
Hemoglobin and red blood cell count must be positive numbers; non-positive values are not valid inputs for this calculator and are not charged.
Is hematocrit a percent or a 0–1 fraction?
Send hematocrit as a percent (for example 45 for 45%), not as 0.45.
Is the RBC indices calculator free?
The browser tool runs free on your device.
Does this diagnose anemia or classify microcytosis?
No. This product only computes MCV, MCH, and MCHC from three CBC scalars. Anemia classification, RDW, and clinical interpretation are different contracts and are not returned here.
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/health/rbc-indices \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"hemoglobin":15,"hematocrit":45,"rbc_count":5}'const res = await fetch("https://api.kit.forhosting.com/health/rbc-indices", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"hemoglobin": 15,
"hematocrit": 45,
"rbc_count": 5
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/health/rbc-indices",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"hemoglobin": 15,
"hematocrit": 45,
"rbc_count": 5
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/rbc-indices", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"hemoglobin":15,"hematocrit":45,"rbc_count":5}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"hemoglobin":15,"hematocrit":45,"rbc_count":5}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/rbc-indices", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"hemoglobin": 15,
"hematocrit": 45,
"rbc_count": 5
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "health.rbc_indices",
"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
Successful API calls cost $0.002 per item; validation failures are not billed.
What MCV, MCH and MCHC measure and which CBC inputs you need
Send required fields hemoglobin, hematocrit, and rbc_count as finite positive numbers; aliases such as hb, hgb, haemoglobin, hct, packed_cell_volume, pcv, rbc, red_blood_cell_count, and erythrocyte_count are accepted when documented. Identical inputs always yield identical JSON because the path is pure arithmetic with no network, no model, no random seed, and no wall clock.
Reading the three indices, units, rounding, and error behaviour
The product contract is explicit on hemoglobin and RBC count: if either is not a positive number the task fails rather than emitting Infinity from a divide-by-zero. Hematocrit is also required to be positive because MCHC divides by hematocrit. On success the response echoes hemoglobin, hematocrit, and rbc_count with stable rounding, then reports mcv in femtolitres, mch in picograms, and mchc in grams per decilitre. Unit labels travel beside those numbers so a client never has to guess: unit_hemoglobin is g/dL, unit_hematocrit is percent, unit_rbc is ×10^12/L, unit_mcv is fL, unit_mch is pg, and unit_mchc is g/dL. formula restates the three Wintrobe equations as a single teaching string, and method is always wintrobe_rbc_indices so downstream code can branch without sniffing shapes. Missing required fields, empty strings, non-finite values, out-of-range readings, and any non-positive hemoglobin, hematocrit, or red blood cell count all fail with invalid_input and are not charged. Do not confuse this endpoint with anemia classifiers, RDW calculators, corrected reticulocyte counts, unit converters that map grams per litre to grams per decilitre, or full CBC interpretation engines—those are different search intents and different contracts. This product only derives the three Wintrobe indices from three validated positive CBC scalars.
API usage, pricing, educational workflows, and practical limits
Send a JSON body with required hemoglobin, hematocrit, and rbc_count values in the conventional teaching units described above. Use the prepaid API when a health SaaS, electronic worksheet, simulation lab, tutoring platform, or school LMS needs a stable contract under KIT balance at $0.002 per successful item; validation failures never consume balance after the engine rejects the request. Pair this endpoint with your own laboratory units and clinical workflow—confirm that hemoglobin is already in grams per decilitre, hematocrit is already a percent rather than a litre-per-litre fraction, and the red-cell count is already in millions per microlitre—then store mcv, mch, and mchc alongside the raw inputs for dashboards and export columns.
Integration use cases
Nursing and medical-school homework
Students submit hemoglobin, hematocrit, and RBC count from a practice CBC and pin expected MCV, MCH, and MCHC JSON in automated checkers with deterministic outputs.
Simulation labs and SaaS backends
Server pipelines that already store CBC fields call a prepaid endpoint for MCV, MCH, and MCHC instead of duplicating the arithmetic in every language.