Therms to kWh converter
1 therm is 29.307107017222 kWh. Turn the gas energy on a North American bill into the kilowatt-hours of an electricity meter with the exact factor instead of the 29.3 shortcut, so you can set gas heating next to a heat pump. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Therms
- 1
- Result
- 29.3071070172 kWh
- Converted
- 29.3071070172
- Kwh
- 29.3071070172
- From unit
- therm
A therms-to-kWh converter turns a natural-gas energy reading in therms into the kilowatt-hour value used on electricity meters, heat-pump comparisons, and SI engineering energy balances. Approximate mental shortcuts such as twenty-nine point three kilowatt-hours per therm are replaced by the full exact constant, so utility checks and lab exports match modern engineering references.
Why therms and kilowatt-hours meet at this exact factor
The kilowatt-hour is the everyday SI-derived unit of energy on electricity meters: one kilowatt of power sustained for one hour equals exactly three million six hundred thousand joules. The therm remains common on North American natural-gas bills, utility rate schedules, and facility energy reports that still quote delivered gas energy in therms rather than joules or kilowatt-hours.
Under the US and International Table convention used by modern conversion tables, one therm equals one hundred thousand International Table British thermal units, and one International Table BTU equals one thousand fifty-five point zero five five eight five two six two joules.
Multiplying those constants and dividing by the exact joule content of one kilowatt-hour yields a single exact multiplication factor: kilowatt-hours equals therms times one hundred thousand times one thousand fifty-five point zero five five eight five two six two over three million six hundred thousand, which is about twenty-nine point three zero seven one kilowatt-hours per therm. That makes the conversion deterministic arithmetic rather than a lookup table.
Other historical energy units exist—the thermochemical BTU is slightly different, and some regions use decatherms or MMBTU—but this tool deliberately hard-codes the US/IT therm constant that natural-gas billing and most web “therms to kWh” searches expect. Teachers can contrast the exact path with the rough twenty-nine point three kilowatt-hours per therm rule of thumb so students see how truncation of the factor accumulates on large seasonal heating loads.
Practical tips, checks, and related searches
Round-trip sanity checks are easy: convert one therm and confirm you receive about twenty-nine point three zero seven one kilowatt-hours under twelve-decimal rounding, or convert ten therms and confirm the result is ten times that factor. If your source quotes decatherms or MMBTU, scale to plain therms first—one decatherm is ten therms and one MMBTU is ten therms under the usual 100000 BTU per therm convention—before calling this tool. Stay inside the absolute range so the product cannot overflow into a non-finite result the solver must reject.
When teaching unit analysis, pair a monthly gas bill in therms with an electricity bill in kilowatt-hours so students see energy, not power, moving across unit systems for heat-pump comparisons. This landing targets people searching for therms to kWh, convert natural gas therms to kilowatt hours, or an exact therm energy calculator; it is not a multi-unit energy hub, not a kWh-to-therms primary form, not a BTU-only converter, and not a volumetric gas-flow tool.
Prefer this capability when the input is already energy in therms and you only need kilowatt-hours; if you must convert among many energy units in one call, use a broader energy unit converter instead. Always keep power and energy labels separate: a furnace rating in BTU per hour is a power quantity, and only the energy consumed over a chosen number of hours, once expressed in therms, belongs in this converter.
What you can do with it
Natural gas bill to electric energy comparisons
Convert monthly or seasonal gas usage in therms into kilowatt-hours for heat-pump COP checks, dual-fuel cost models, and SI facility energy dashboards with the same exact factor every row.
FAQ
How many kWh are in one therm?
Exactly 100000 × 1055.05585262 / 3600000 kilowatt-hours for the US/IT therm used by this tool: about 29.307107017222 kWh per therm. Formula: kWh = therms × (100000 × 1055.05585262 / 3600000).
Is this power or energy?
Energy only. Input is therms (energy). If your label is a rate such as therms per day, multiply by the number of days first to obtain total energy, then convert.
Is the therms to kWh converter free?
The browser tool is free and runs locally.
How do I convert decatherms or MMBTU to kWh?
Scale to plain therms first: one decatherm is 10 therms, and one MMBTU is also 10 therms under the usual convention. Then enter the therms, and 10 therms gives ten times 29.307107017222 kWh.
Why not just use 29.3 kWh per therm?
The shortcut drops digits from the exact factor of 29.307107017222 kWh per therm. On a single bill the gap is small, but over large seasonal heating loads the truncation adds up.
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/therms-to-kwh \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"therms":1}'const res = await fetch("https://api.kit.forhosting.com/conv/therms-to-kwh", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"therms": 1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/therms-to-kwh",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"therms": 1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/therms-to-kwh", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"therms":1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"therms":1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/therms-to-kwh", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"therms": 1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.therms_to_kwh",
"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
Invalid or missing input fails with a clear invalid_input error instead of inventing a number.
How to call the API and what comes back
Absolute values must stay within the published limit of one trillion. Prefer bare numbers when you control the client; string numbers are accepted only when they match a strict finite numeric pattern without unit suffixes or thousand separators. Send a JSON body with one required finite number field named therms. Aliases therm, value, energy, gas_therms, and thm are accepted so SDK clients and form posts can use the name that fits the product. On success the response echoes rounded therms, sets kwh, result, and converted to the same rounded kilowatt-hour magnitude, unit to the token kWh, from_unit to therm and to_unit to kWh, factor and kwh_per_therm to the rounded exact ratio, joules_per_therm to one hundred five million five hundred five thousand five hundred eighty-five point two six two, joules_per_kwh to three million six hundred thousand, btu_per_therm to one hundred thousand, formula to the string kWh equals therms times the joule ratio, message to a short English summary, and steps to an ordered array of substitution lines. Failed validation—missing fields, non-finite numbers, bare plus or minus signs, non-numeric strings, values outside absolute limits, or a non-finite converted result—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item and zero marginal unit price. Do not send cubic feet of gas when you need energy: volumetric gas must be converted to therms using the supplier heating value before calling this tool.
Practical tips, checks, and related searches
Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately omit therms or pass text.
Integration use cases
Homework and exam unit checks
Students convert textbook therm readings to kWh and compare hand work against deterministic steps before submitting worksheets or coding kata fixtures.
Facilities and utility data alignment
Plant logs and utility exports that quote therms can be normalized to kWh for SI datasheets, carbon models, and API payloads without fragile hand-typed factor tables.
Technical questions
Which therm definition do you use?
The US/International Table therm: 1 therm = 100000 BTU_IT, with 1 BTU_IT = 1055.05585262 J. This is the definition most natural-gas bills and modern engineering converters use for therms to kWh.
What happens on invalid input?
Missing fields, non-finite values, non-numeric strings, or values outside the absolute limits return invalid_input and are never charged.