Molar flow rate converter
Switch a molar flow between seconds, minutes and hours, in moles or kilomoles: 1 mol/s is 3.6 kmol/h. Match a reactor design basis to plant reporting units without re-deriving time and kilo factors. 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
- mol/s
- Target unit
- kmol/h
- Result
- 3.6
- From label
- moles per second
- To label
- kilomoles per hour
- Mol s
- 1
A molar flow rate converter turns a chemical-process throughput written in moles over time into another time base or kilo-scale without hunting reactor design notes, Aspen stream reports, or mixed SI tables.
Supported units and how the conversion is computed
The converter accepts six molar flow-rate families under stable canonical codes: mol/s for moles per second, mol/min for moles per minute, mol/h for moles per hour, kmol/s for kilomoles per second, kmol/min for kilomoles per minute, and kmol/h for kilomoles per hour.
Factors follow SI definitions: one kilomole is exactly one thousand moles, one minute is sixty seconds, and one hour is three thousand six hundred seconds, so one mole per hour is exactly one divided by three thousand six hundred moles per second and one kilomole per hour is one thousand divided by three thousand six hundred moles per second.
Because the intermediate is always moles per second, converting A to B and B to A is consistent up to the published rounding of twelve decimal places, and there is no pairwise matrix that can drift out of sync. Mass flow units such as kilograms per second and volumetric units such as liters per second are intentionally out of scope so process and reaction-engineering users who expect molar SI rates get predictable results without density or composition assumptions.
Where molar flow conversions fit in process work
Use the free in-browser molar flow rate converter when you need a quick moles-per-second-to-kilomoles-per-hour, moles-per-hour-to-moles-per-minute, or kilomoles-per-hour-to-moles-per-second check while reading a reactor design problem, process flow diagram, simulation stream table, or homework assignment. Open the page, enter the number and units, and copy the result without installing a spreadsheet, a unit library, or a desktop calculator pack. Source inputs follow the same retention rules as other KIT parse items, and results are safe to cache because the algorithm is fully deterministic.
Authors shipping mobile apps or chatbots can map the result and formula fields directly into cards that show both the number and the conversion path operators, students, and process engineers expect on paper.
What you can do with it
Reactor and plant design
Convert mol/s design bases to kmol/h plant reporting units so PFDs, mass balances, and vendor packages share one molar-flow language.
Process simulation hand-off
Translate Aspen, HYSYS, or spreadsheet stream molar rates between mol/h, mol/s, and kmol/h without re-deriving time and kilo factors.
FAQ
Which molar flow-rate units does this converter support?
Moles per second (mol/s), moles per minute (mol/min), moles per hour (mol/h or mol/hr), kilomoles per second (kmol/s), kilomoles per minute (kmol/min), and kilomoles per hour (kmol/h or kmol/hr).
What happens if I send an unknown unit?
The message names the field and lists supported units. Validation failures are not charged.
Is the molar flow rate converter free?
The browser tool runs free on your device.
How many kmol/h is 1 mol/s?
1 mol/s is 3.6 kmol/h: multiply by the 3600 seconds in an hour, then divide by the 1000 moles in a kilomole. The other way round, 1 kmol/h is about 0.277777777778 mol/s.
Can it convert to kilograms or litres per second?
No. Mass and volume flows need a density or a composition, which this converter never assumes. It stays with molar rates, so the results are predictable.
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/molar-flow-rate \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"mol/s","to":"kmol/h"}'const res = await fetch("https://api.kit.forhosting.com/conv/molar-flow-rate", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "mol/s",
"to": "kmol/h"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/molar-flow-rate",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "mol/s",
"to": "kmol/h"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/molar-flow-rate", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"mol/s","to":"kmol/h"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"mol/s","to":"kmol/h"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/molar-flow-rate", 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": "mol/s",
"to": "kmol/h"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.molar_flow_rate",
"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
The browser tool runs free on your device; the prepaid API charges $0.002 per successful item when pipelines need the same contract from servers and automation.
Supported units and how the conversion is computed
Friendly aliases such as moles per second, moles per hour, kilomoles per hour, mol/hr, kmol/hr, moles per minute, kilomole per second, and compact codes like molh or kmolph are normalized case-insensitively so forms and APIs can pass either short codes or full names. Every request multiplies the input value by the exact moles-per-second factor for the source, then divides by the moles-per-second factor for the target.
Request shape, response fields, and unknown-unit errors
The error message names the bad field and lists the supported set so clients can correct forms without guessing. Negative values are allowed when you need signed molar-flow deltas in engineering pipelines; zero converts cleanly to zero in every target unit. Send a JSON body with three required fields: value as a finite number, from as the source unit string, and to as the target unit string. Aliases amount, quantity, rate, and flow are accepted for value; unit_from and source for from; unit_to and target for to. On success the response echoes the canonical from and to codes, human-readable from_label and to_label strings, the converted result, the intermediate mol_s quantity in moles per second, the dimensionless factor from source to target, a short formula line suitable for UI display, the method tag molar_flow_rate_si, and the fixed list of units_supported. Missing value, non-finite numbers such as NaN or Infinity, missing unit fields, and any token that does not map to a supported unit fail with invalid_input and are not charged after the engine rejects the request. Identical inputs always yield identical JSON because the path is pure arithmetic with no randomness, no remote lookup, and no dependence on the wall clock, which makes the endpoint safe to pin in continuous-integration goldens and SDK contract tests. Plant-scale kilomole-per-hour streams and laboratory mole-per-second dosing rates share the same code path, so extreme magnitude pairs remain well-defined as long as IEEE double precision can represent the intermediate moles-per-second product.
Browser use, API pricing, and everyday workflows
Switch to the prepaid API when a process digital twin, lab automation script, batch-recipe tool, or engineering homework checker must convert molar flow at scale under a stable KIT contract at $0.002 per successful item; validation failures that raise invalid_input do not consume balance after rejection. Pair this endpoint with the mass flow rate converter when a product pipeline needs both mole and mass rate families after applying molecular weight, or call it alone when search traffic is specifically for molar flow rate conversion—moles per second, moles per hour, and kilomoles per hour—rather than a general unit switchboard.
Integration use cases
Labs and automation pipelines
Normalize dosing and reactor feed tags to mol/s or mol/min in scripts with a prepaid, deterministic API contract.
Technical questions
How many moles are in one kilomole?
Exactly one thousand. All kmol/* factors use the SI definition 1 kmol = 1000 mol with no approximate prefixes.
How do I convert 1 mol/s to kilomoles per hour?
Send JSON with value: 1, from: "mol/s", to: "kmol/h". The response result field is the equivalent molar flow in kilomoles per hour, plus a mol_s intermediate and a readable formula.