MPa to PSI converter
Multiply megapascals by 145.038 to get psi: 1 MPa is 145.038 psi and 250 MPa is 36259.5 psi. Move mill-certificate yield values and SI pump ratings into the psi columns of US drawings and gauges. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Mpa
- 1
- Result
- 145.038 psi
- Converted
- 145.038
- Psi
- 145.038
- Factor
- 145.038
An MPa-to-psi conversion turns a pressure written in megapascals into pounds per square inch, the everyday United States customary unit on hydraulic nameplates, compressor charts, tyre tables, and ASME process sheets. One megapascal is taken as one hundred forty-five point zero three eight psi, the conventional engineering factor this calculator hard-codes: multiply the finite megapascal value by one hundred forty-five point zero three eight.
Why megapascals become psi by multiplying by 145.038
The megapascal is one million pascals, the SI-derived pressure unit that European mill certificates, ISO hydraulic ratings, and many finite-element decks already print. Pounds per square inch remain the everyday United States customary unit on tyre placards, ASME yield tables, compressor nameplates, and North American process sheets. The conventional engineering bridge between those two names is a single multiplication: one megapascal equals one hundred forty-five point zero three eight pounds per square inch, so psi equals MPa times one hundred forty-five point zero three eight.
That six-significant-figure factor is the published identity used on data sheets and classroom conversion tables; it is not a fourteen-point-seven atmosphere shortcut and it is not a trip through bar or torr. Materials and hydraulics engineers still search convert MPa to psi because drawings mix the two families, not because the arithmetic is hard: dropping the decimal or using one hundred forty-five even can shift a yield or a working pressure by tens of psi.
This capability hard-codes that published factor and never routes through atmospheres, kilopascals, or ksi unless you do so on your side. Zero megapascals maps to zero psi. Negative values are allowed because vacuum gauge readings and compressive stresses are signed, not lengths.
What you can do with it
Mill certificates and yield tables
Convert MPa yield and tensile values from mill certs into psi columns for United States drawings, BOM rows, and ASME comparison tables with the same published times-145.038 factor.
Hydraulic and pressure-vessel nameplates
Bridge SI megapascal ratings on pumps, accumulators, and vessel datasheets into psi fields that match gauge faces and North American process sheets.
Homework and finite-element unit checks
Students and analysts convert classroom MPa stresses to psi and compare hand work against deterministic steps that show the published 145.038 identity.
FAQ
Why is the conversion factor 145.038?
Multiply the finite megapascal value by that factor. There is no approximate times-145 mode.
Are negative MPa values allowed?
Yes. Signed compressive or vacuum readings convert with the same factor. Zero maps to zero psi.
Is the MPa to psi conversion free?
The browser tool is free and runs locally.
How many psi is 250 MPa?
250 MPa is 36259.5 psi: just multiply by 145.038. It is a quick check for mill certificates, which often print yield and tensile strength in megapascals.
What goes wrong if I round the factor to 145?
Dropping the decimals shifts large values by tens of psi. On a yield strength or a working pressure, that gap matters when you compare against ASME tables or a gauge face.
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/mpa-to-psi-conversion \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"mpa":1}'const res = await fetch("https://api.kit.forhosting.com/conv/mpa-to-psi-conversion", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"mpa": 1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/mpa-to-psi-conversion",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"mpa": 1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/mpa-to-psi-conversion", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"mpa":1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"mpa":1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/mpa-to-psi-conversion", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"mpa": 1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.mpa_to_psi_conversion",
"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
Missing fields and non-finite numbers fail with invalid_input instead of inventing a reading.
Why megapascals become psi by multiplying by 145.038
The result is rounded only to keep JSON stable across runtimes, not because the factor itself is left for the caller to invent.
Input contract, response shape, and error behaviour
Prefer sending bare numbers when you control the client. Round-trip sanity checks are easy: convert one megapascal and confirm you receive one hundred forty-five point zero three eight psi, or convert two hundred fifty megapascals and confirm thirty-six thousand two hundred fifty-nine point five psi. Send a JSON body with one required finite number field named mpa. Aliases megapascal, megapascals, value, pressure, and mpa_value are accepted so SDK clients and form posts can use the name that fits the product. The value must be a JSON number or a strict numeric string without units, thousand separators, or currency symbols. Absolute values must stay within the published limit of one trillion so the product stays finite in IEEE double precision. On success the response echoes rounded mpa, sets psi, result, and converted to the same rounded pound-per-square-inch magnitude, factor to one hundred forty-five point zero three eight, factor_label to the published identity, formula to the string psi equals mpa times one hundred forty-five point zero three eight, method to mpa_times_145_038, from_unit to MPa, to_unit and unit to psi, plus a short English message and an ordered steps array of substitution lines. Failed validation—missing fields, non-finite numbers, bare plus or minus signs, non-numeric strings, values outside the absolute limit, 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.
Where a dedicated MPa-to-psi landing earns its keep
Prefer this landing when the search intent is specifically MPa to psi, not a general multi-unit pressure hub and not a ksi converter that would leave the megapascal identity to you. Steel mill certificates that print yield in megapascals while a United States drawing still wants psi, hydraulic and pressure-vessel sheets that mix SI ratings with pound-force gauges, classroom checkers that must mark times one hundred forty-five point zero three eight without a spreadsheet, and finite-element decks that store psi internally but receive MPa material cards all need the same deterministic contract. Stay inside the published range so the multiply cannot overflow. Pair the published path with a mental check: multiply by one hundred forty-five and add a few extra psi; if the API disagrees by more than rounding, the input was not a finite megapascal value. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately omit mpa or pass text. Successful conversions bill as one item at $0.002; validation failures are free.
Technical questions
How do I convert MPa to psi?
Send JSON with mpa set to a finite number (for example mpa: 1). The response returns psi, result, and converted equal to mpa × 145.038, plus a formula string. One megapascal is 145.038 psi.
What happens on missing or non-numeric input?
The API returns invalid_input naming the problem (for example a missing mpa field or a non-finite number). Failed tasks are not charged.