Thermal conductance converter
1 W/K is 1.895634240627 BTU/(h·°F). Convert a heat flow per degree of temperature difference between SI, calorie and BTU units, and get the factor applied plus step-by-step lines you can paste into a report. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Value
- 1
- Source unit: W/K, BTU/
- W/K
- Target unit: W/K, BTU/
- BTU/(h·°F)
- Result
- 1.8956342406
- Converted
- 1.8956342406
- Value w per k
- 1
- Factor
- 1.8956342406
A thermal conductance converter turns one heat-transfer-rate-per-temperature-difference reading into another unit without spreadsheet formulas or mental factor tables. Enter a finite value plus a source unit and a target unit among watts per kelvin, British thermal units per hour-fahrenheit, thermochemical calories per second-kelvin, and SI multiples such as kilowatts and milliwatts per kelvin; the tool returns the converted conductance, the SI intermediate in W/K, the exact unit factor applied, and step-by-step substitution lines you can paste into a report. Thermal engineers comparing joint or contact conductance datasheets, students converting textbook tables between SI and customary units, HVAC designers reading mixed property charts, and electronics cooling teams aligning component specs all need the same deterministic path.
Which thermal conductance units are supported and how conversion works
This capability converts among everyday thermal conductance units that dominate heat-transfer tables, electronics cooling datasheets, building envelope notes, and engineering homework. Watts per kelvin (W/K) are the SI coherent unit and the internal hub: every conversion multiplies the input by how many watts per kelvin equal one source unit, then divides by how many watts per kelvin equal one target unit. Because a kelvin interval equals a celsius interval, W/°C is treated as identical to W/K for conversion purposes.
Kilowatts per kelvin and milliwatts per kelvin scale by exact powers of ten. Thermochemical calories per second-kelvin use the exact factor four point one eight four, from one thermochemical calorie of four point one eight four joules per second. Kilocalories per hour-celsius use four thousand one hundred eighty-four joules per kilocalorie divided by three thousand six hundred seconds per hour.
British thermal units per hour-fahrenheit use the International Table BTU of one thousand fifty-five point zero five five eight five two six two joules, three thousand six hundred seconds per hour, and the Fahrenheit interval of five ninths of a kelvin. Same-unit requests succeed and return the input magnitude with a short message that no change of unit was required.
Practical tips, limits, and when to use this landing
Prefer sending bare numbers for value when you control the client; string numbers are accepted only when they match a strict finite numeric pattern without currency symbols or thousand separators. 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.
When teaching unit analysis, pair classic examples such as one watt per kelvin equaling about one point eight nine five six BTU per hour-fahrenheit, and four point one eight four watts per kelvin equaling one calorie per second-kelvin. Stay inside the absolute range so intermediate SI values cannot overflow.
This landing targets people searching for a thermal conductance converter, W/K to BTU/h·°F, cal/s to SI, or watts per kelvin online; it is not a thermal conductivity (W/(m·K)) converter, not a Fourier wall heat-flow calculator that needs area and thickness, and not a specific heat capacity tool.
What you can do with it
Electronics cooling datasheet alignment
Thermal engineers convert contact and package thermal conductance from W/K into BTU/(h·°F) or cal/(s·K) so mixed SI and customary design reviews share one numeric scale.
HVAC and building envelope checks
Designers convert joint and window conductance tables between customary BTU/(h·°F) and SI W/K for energy models, code compliance notes, and cross-standard handoffs.
Lab and textbook unit drills
Students and lab techs convert thermal conductance homework values between calorie-based lab books and SI reports without hand factor mistakes.
FAQ
How is one BTU per hour-fahrenheit defined here?
One BTU/(h·°F) equals 1055.05585262 × 9 / (3600 × 5) W/K using the International Table BTU, the hour, and the Fahrenheit temperature interval of 5/9 kelvin.
Is the thermal conductance converter free?
The browser tool is free and runs locally.
How many BTU per hour-°F is 1 W/K?
1 W/K equals 1.895634240627 BTU/(h·°F). Going the other way, 1 BTU/(h·°F) is 0.52752792631 W/K, so a round trip gives back your starting value within the twelve-decimal rounding.
Is W/°C the same as W/K?
Yes. A step of one kelvin is the same size as a step of one degree Celsius, so a conductance written in W/°C keeps exactly the same number in W/K.
How do I convert cal/(s·K) to W/K?
Multiply by 4.184. One thermochemical calorie is 4.184 joules, so 1 cal/(s·K) equals 4.184 W/K; to go back, divide by the same number.
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/thermal-conductance \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"W/K","to":"BTU/(h·°F)"}'const res = await fetch("https://api.kit.forhosting.com/conv/thermal-conductance", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "W/K",
"to": "BTU/(h·°F)"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/thermal-conductance",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "W/K",
"to": "BTU/(h·°F)"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/thermal-conductance", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"W/K","to":"BTU/(h·°F)"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"W/K","to":"BTU/(h·°F)"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/thermal-conductance", 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": "W/K",
"to": "BTU/(h·°F)"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.thermal_conductance",
"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 | 1000000000000 |
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 fail with a clear invalid_input error instead of silent wrong factors.
Which thermal conductance units are supported and how conversion works
Common aliases are accepted case-insensitively: W/C and watts per kelvin for W/K; BTU/h/F, BTU/hr/F, and btu per hour fahrenheit for BTU/(h·°F); cal/s/K, cal/s, and calories per second kelvin for cal/(s·K); plus kW/K, mW/K, and kcal/h/C forms. If the name is not on that list the solver rejects the request with invalid_input naming the bad field and listing supported units, so clients never guess whether a typo produced a wrong number. Absolute magnitude must stay within the published one-trillion limit so intermediate products remain finite in IEEE double precision on the Worker and in the browser.
How to call the API and read the response
Value must be a finite number or a strict numeric string within absolute limits of one trillion. Wire this into dashboards, mobile clients, or batch jobs that already hold a thermal conductance reading and only need a second unit for display, datasheet comparison, or regulatory reporting without shipping floating conversion tables in every app binary. Send a JSON body with three required fields: value (aliases g, amount, n, and conductance), from (aliases from_unit, unit_from, and source), and to (aliases to_unit, unit_to, and target). From and to must resolve to supported unit names 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, value_w_per_k as the SI intermediate, unit as the target label, factor as the from-to multiplier, formula as the short equation string, message as an English summary, steps as ordered substitution lines, and supported_units as the six canonical identifiers. Failed validation—missing fields, non-finite numbers, values outside absolute limits, or an unknown unit name—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item and zero marginal unit price.
Practical tips, limits, and when to use this landing
Normalize display labels on your side if you need locale-specific spellings—this API always returns the short canonical tokens W/K, kW/K, mW/K, cal/(s·K), kcal/(h·°C), and BTU/(h·°F) so automated tests stay stable. Prefer this capability when both endpoints are among the six supported thermal-conductance units and you need deterministic factors and step strings; if you need heat flow Q through a wall from k, A, ΔT, and L, use the dedicated thermal conduction calculator instead. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when clients deliberately probe unknown unit names.
Technical questions
Which thermal conductance units can I convert?
Watts per kelvin (W/K), kilowatts per kelvin (kW/K), milliwatts per kelvin (mW/K), thermochemical calories per second-kelvin (cal/(s·K)), kilocalories per hour-celsius (kcal/(h·°C)), and British thermal units per hour-fahrenheit (BTU/(h·°F)), including common aliases such as W/C, cal/s, and BTU/h/F.
What happens if I send an unknown unit name?
The API returns invalid_input, names the bad field, and lists the supported units. The failed task is not charged.
Are results deterministic across browser and API?
Yes. Handler and widget share the same lib.js solve path with fixed conversion factors and twelve-decimal rounding, so golden examples match production.