Radiation converter
Convert radiation readings within the right family: 1 curie is 37 billion becquerels and 1 gray is 100 rad. Activity and dose are never mixed, so old records and new certificates agree. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Value
- 1
- From
- Ci
- To
- Bq
- Result
- 37,000,000,000 Bq
- Converted
- 37,000,000,000
- Family
- activity
- Hub
- Bq
A radiation converter turns a radioactivity or dose magnitude from one supported unit into another without spreadsheet factors or guessed prefixes. Enter a finite value, a source unit, and a target unit among becquerel (Bq), curie (Ci), gray (Gy), rad, sievert (Sv), and rem; the tool returns the converted magnitude, the physical family used as the conversion hub, the exact factor applied, and a short formula you can paste into a lab notebook or report. Activity units convert through becquerels, absorbed-dose units through grays, and equivalent-dose units through sieverts. Mixing families—for example becquerels to grays—is rejected because activity, absorbed dose, and equivalent dose are different physical quantities.
Which radiation units are supported and how families convert
This radiation converter covers the six unit names that dominate search queries for a general radiation converter: becquerel (Bq) and curie (Ci) for radioactivity, gray (Gy) and rad for absorbed dose, and sievert (Sv) and rem for equivalent dose. Those three families are not interchangeable. Radioactivity counts nuclear transformations per second; absorbed dose measures energy deposited per unit mass; equivalent dose weights that energy by radiation type for protection quantities.
Converting one curie to becquerels is exact because both count the same activity. Converting one gray to rad is exact because both measure the same absorbed energy per mass. Converting one sievert to rem is exact because both measure the same protection quantity.
The solver therefore routes every pair through a single SI hub inside the matching family: activity through Bq with the exact factor one curie equals 3.7 times ten to the ten becquerels; absorbed dose through Gy with one rad equals 0.01 gray; equivalent dose through Sv with one rem equals 0.01 sievert. English names such as becquerel, curie, gray, sievert, and rem resolve to the same canonical symbols. Same-unit requests succeed and return the input magnitude with a short message that no change of unit was required.
Where a unified radiation converter earns its keep
Prefer this landing when a person searches for a radiation converter and wants one form that covers the six everyday unit names rather than three specialized family tools. Health-physics technicians comparing a curie inventory with a becquerel certificate, radiation oncology staff reconciling historical rad charts with modern gray prescriptions, and protection officers converting rem totals to sieverts all hit the same search phrase even though the physical quantities differ. This capability answers that phrase honestly: it converts within a family and refuses to pretend that activity is dose.
Round-trip checks are straightforward: convert A to B and B back to A and confirm you recover the original within the published twelve-decimal rounding. This landing is not a decay-chain solver, not an exposure (roentgen or coulomb per kilogram) converter, not a linear-energy-transfer tool, and not a mass-attenuation calculator. Dedicated sibling capabilities exist for radioactivity with SI prefixes, absorbed dose including milligray and erg per gram, and equivalent dose including millisievert and microsievert; use those when you need prefix coverage rather than the six-name general converter.
What you can do with it
Curie inventories to becquerel certificates
Nuclear-medicine and waste-tracking teams convert sealed-source and inventory figures from Ci to Bq with the exact 3.7e10 factor before certificates and shipping papers.
Historical rad charts to gray protocols
Radiation oncology and therapy planning systems receive legacy prescriptions in rad while modern protocols use Gy; staff convert absorbed dose once with exact factors before plan approval.
Protection totals from rem to sievert
Radiation-protection officers convert annual rem totals to sieverts for reports that must use SI equivalent-dose units without mixing activity or absorbed-dose tables.
FAQ
Which radiation units can I convert?
Bq and Ci (activity), Gy and rad (absorbed dose), and Sv and rem (equivalent dose). English names such as becquerel, curie, gray, and sievert are accepted. Source and target must belong to the same family.
Why can't I convert Bq to Gy or Sv?
Becquerel measures activity, gray measures absorbed dose, and sievert measures equivalent dose. Those are different physical quantities.
What factor converts curie to becquerel?
One curie equals 3.7×10¹⁰ becquerels exactly. One gray equals 100 rad, and one sievert equals 100 rem. The response includes result, factor, hub, and formula so you can show the substitution.
What happens if a unit name is unsupported?
Non-finite values fail the same way. Invalid input is not billed.
Why do older records use rad and rem instead of gray and sievert?
Rad and rem are the older units found in historical treatment charts and dose totals, while gray and sievert are the modern SI units. One rad is 0.01 gray and one rem is 0.01 sievert, so the conversion is exact.
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/conv/radiation-converter \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"Ci","to":"Bq"}'const res = await fetch("https://api.kit.forhosting.com/conv/radiation-converter", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "Ci",
"to": "Bq"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/radiation-converter",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "Ci",
"to": "Bq"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/radiation-converter", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"Ci","to":"Bq"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"Ci","to":"Bq"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/radiation-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
{
"value": 1,
"from": "Ci",
"to": "Bq"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.radiation_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.
Limits
max_abs | 1000000000000000000 |
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
Unknown unit names and non-finite values fail with invalid_input instead of a silent wrong number.
Which radiation units are supported and how families convert
Converting becquerels to grays, or grays to sieverts, is not a unit conversion at all—it would require energy per disintegration, irradiated mass, and radiation weighting factors that this endpoint does not accept. If the name is not on the supported list, or if source and target sit in different families, the request fails with invalid_input naming the problem instead of inventing a factor.
Input contract, response shape, and error behaviour
Value must be a finite number or a strict numeric string within absolute limits of one quintillion. Classic teaching pairs include one curie equals thirty-seven billion becquerels, one gray equals one hundred rad, and one sievert equals one hundred rem. Wire this into health-physics notebooks, teaching labs, archive migration jobs, or dashboards that already hold a radiation reading and only need a second unit for display, certificate comparison, or report wording without shipping conversion tables in every app binary. Send a JSON body with three required fields: value (aliases amount, n, dose, and activity), from (aliases from_unit, unit_from, and source), and to (aliases to_unit, unit_to, and target). From and to must resolve to Bq, Ci, Gy, rad, Sv, or rem after alias normalization. On success the response echoes the rounded input value, canonical from and to labels, result and converted set to the same rounded target magnitude, family as activity, absorbed_dose, or equivalent_dose, hub as Bq, Gy, or Sv, value_hub as the SI intermediate, unit as the target label, factor as the from-to multiplier, formula as a short equation string, message as an English summary, and supported_units as the six canonical identifiers. Failed validation—missing fields, non-finite numbers, values outside absolute limits, an unknown unit name, or a cross-family pair—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item.
Where a unified radiation converter earns its keep
Stay inside IEEE double-precision limits; extremely large inventories should use a coarser target unit such as Ci or Gy rather than expanding everything to Bq or rad. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when clients probe unknown unit names or accidentally mix families.
Technical questions
What does the radiation converter cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.