Qp/Qs ratio calculator
Qp/Qs ratio calculator: enter your values and see a clear result on this page. Free for individual checks; API from $0.002.
Run — free
Runs in your browser. Free, unlimited — your data never leaves this page.
How to use it
Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.
Check your inputs
Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.
Use it again or automate it
Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.
What you can do with it
Get an answer now
Enter one set of values and see the result without building a spreadsheet or script.
Compare scenarios
Change one value at a time and rerun the calculation to understand what affects the result.
Automate repeated work
Use the API when the same calculation needs to run inside your product or workflow.
FAQ
How is the Qp/Qs ratio calculated from oxygen saturations?
Qp/Qs = (SaO2 − SvO2) / (SpvO2 − SpaO2). Send sat_systemic_arterial, sat_mixed_venous, sat_pulmonary_venous, and sat_pulmonary_arterial as percents from 0 to 100. The response includes qp_qs, qp_qs_rounded, numerator, denominator, and shunt_direction.
What saturations do I need for a Qp/Qs ratio?
Four oxygen saturations in percent: systemic arterial (aorta), mixed venous (typically SVC), pulmonary venous (often assumed near 98% if not sampled), and pulmonary arterial. Aliases such as sao2, svo2, spvo2, and spao2 are accepted.
What happens if a saturation is outside 0 to 100?
The task fails with invalid_input naming the field. Oxygen saturations must be between 0 and 100 inclusive; values outside that range are not billed.
What does Qp/Qs greater than one mean?
Educationally, Qp/Qs > 1 is labeled left_to_right (pulmonary flow exceeds systemic flow). Qp/Qs = 1 is balanced, and 0 ≤ Qp/Qs < 1 is right_to_left. These labels are teaching aids, not a diagnosis or surgical threshold.
What does the Qp/Qs ratio calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.
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/health/qp-qs-ratio \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"items":["valor-1","valor-2"]}'const res = await fetch("https://api.kit.forhosting.com/health/qp-qs-ratio", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"items": [
"valor-1",
"valor-2"
]
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/health/qp-qs-ratio",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"items": [
"valor-1",
"valor-2"
]
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/qp-qs-ratio", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"items":["valor-1","valor-2"]}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"items":["valor-1","valor-2"]}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/qp-qs-ratio", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"items": [
"valor-1",
"valor-2"
]
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "health.qp_qs_ratio",
"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. |