Volume flow rate converter
Switch a flow rate between L/s, m³/h, US gallons per minute and cubic feet per minute: 1 L/s is 15.850323141489 gpm. Handy for pump curves, drip irrigation schedules, water quotes and HVAC airflow. 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
- L/s
- Target unit
- Gpm
- Result
- 15.8503231415
- From label
- liters per second
- To label
- US gallons per minute
- Lps
- 1
A volume flow rate converter turns a volumetric throughput figure written in one unit into another without hunting pump curves, HVAC tables, or mixed SI and US customary factors.
Supported units and how the conversion is computed
The converter accepts four volumetric flow-rate families under stable canonical codes: L/s for liters per second, m3/h for cubic meters per hour, gpm for US liquid gallons per minute, and cfm for cubic feet per minute.
Factors follow SI definitions and NIST US liquid measures: one cubic meter per hour is one thousand liters divided by three thousand six hundred seconds, one US gallon per minute is three point seven eight five four one one seven eight four liters divided by sixty seconds, and one cubic foot per minute uses the international foot of exactly zero point three zero four eight meters cubed then divided by sixty.
Because the intermediate is always liters 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. UK imperial gallons and mass-flow units such as kilograms per second are intentionally out of scope so pump, irrigation, and HVAC users who expect volumetric US liquid and SI rates get predictable results.
For pumps, irrigation and HVAC airflow
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, technicians, and students expect on paper.
What you can do with it
Pumps and irrigation
Convert liters per second and cubic meters per hour to US gallons per minute so pump curves, drip schedules, and municipal water quotes share one rate language.
FAQ
Which flow-rate units does this converter support?
Liters per second (L/s), cubic meters per hour (m3/h or m³/h), US liquid gallons per minute (gpm or gal/min), and cubic feet per minute (cfm or ft3/min).
Are gallons US or UK?
US liquid gallons only (3.785411784 L). Imperial UK gallons are not supported so gpm results stay unambiguous for US liquid volumetric flow.
How do I convert 1 L/s to gallons per minute?
The response result field is the equivalent flow in US gallons per minute, plus an lps intermediate and a readable formula.
What happens if I send an unknown unit?
The message names the field and lists supported units. Validation failures are not charged.
Is the volume flow rate converter free?
The browser tool runs free on your device.
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/flow-rate \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"L/s","to":"gpm"}'const res = await fetch("https://api.kit.forhosting.com/conv/flow-rate", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "L/s",
"to": "gpm"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/flow-rate",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "L/s",
"to": "gpm"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/flow-rate", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"L/s","to":"gpm"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"L/s","to":"gpm"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/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": "L/s",
"to": "gpm"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.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 liters per second, cubic meters per hour, gallons per minute, gal/min, cubic feet per minute, ft3/min, m³/h, GPM, and CFM 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 liters-per-second factor for the source, then divides by the liters-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 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 lps quantity in liters per second, the dimensionless factor from source to target, a short formula line suitable for UI display, the method tag flow_rate_si_us_liquid, 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. Large industrial rates and small laboratory drips share the same code path, so extreme magnitude pairs remain well-defined as long as IEEE double precision can represent the intermediate liters-per-second product.
Browser use, API pricing, and everyday workflows
Switch to the prepaid API when a SCADA bridge, building-management dashboard, water-utility billing tool, lab automation script, or engineering homework checker must convert volumetric 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 static volume converter when a product pipeline needs both capacity and rate families, or call it alone when search traffic is specifically for volume flow rate conversion—liters per second, cubic meters per hour, gallons per minute, and cubic feet per minute—rather than a general unit switchboard.
Integration use cases
HVAC and ventilation
Translate cubic feet per minute and cubic meters per hour for air-handler sizing, duct takeoffs, and commissioning reports when vendors mix SI and US labels.
Process and lab pipelines
Normalize tank fill rates, reagent dosing, and SCADA tags to L/s or GPM in automation scripts with a prepaid, deterministic API contract.