Snow-to-liquid ratio calculator
At a 10:1 ratio, 0.5 inches of liquid water becomes 5 inches of snow; enter a measured snow depth instead and you get the ratio that actually fell. The calculator uses your ratio and never invents one. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Liquid precip
- 0.5
- Snow to liquid ratio
- 10
- Calculation mode
- accumulate
- Snow depth
- 5
Winter forecasts and storm post-mortems always come back to the same question: how much snow will (or did) fall for a given liquid water amount? The snow-to-liquid ratio (SLR) answers that link. A classic 10:1 ratio means ten inches of snow for every inch of liquid-equivalent precipitation; colder, fluffier storms may run 15:1 or higher, while wet coastal snow can drop toward 6:1 or less. This snow-to-liquid ratio accumulation calculator multiplies liquid precipitation by a chosen ratio to estimate snow depth, or divides measured snow depth by liquid equivalent to recover the ratio that actually occurred. Depths stay in whatever linear unit you use—millimetres, centimetres, or inches—so long as liquid and snow share the same unit. Negative liquid precipitation is rejected as invalid input, matching physical sense and keeping automation pipelines from silently inventing snow from impossible gauges.
What snow-to-liquid ratio means and how accumulation is computed
Snow-to-liquid ratio is the dimensionless quotient of snow depth over liquid-equivalent precipitation depth when both are expressed in the same linear unit. If a storm drops half an inch of liquid water and the atmosphere supports a 12:1 ratio, expected snow accumulation is six inches: snow equals liquid times ratio. Conversely, if a snow board measures eight inches of snow and the co-located liquid gauge records 0.8 inches of meltwater, the observed ratio is ten.
Meteorologists, ski-area planners, and municipal snow desks use this relationship every winter because quantitative precipitation forecasts (QPF) are often issued as liquid water, while the public and operations teams need snow depth. Temperature aloft, moisture, and crystal habit shift the ratio from storm to storm and even hour to hour within one event; a fixed 10:1 rule of thumb is only a starting point. This calculator does not invent a climatological ratio for you—it applies the ratio you supply, or it recovers the ratio from the two depths you measured.
That keeps the tool honest for homework, field notes, and automated alert rules that already know which ratio scenario they want to test.
Who uses the snow-to-liquid ratio, and when
Municipal public-works dashboards estimate plow hours and salt burn from forecast liquid times an operations-chosen ratio, then after the storm compare board measurements to liquid gauges to log the realised ratio for after-action reports. Ski resorts and avalanche programs track storm totals in both water equivalent and settled snow; inferring ratio from two sensors flags when density assumptions broke. Citizen science notebooks and home weather stations can post liquid and snow board readings and store the derived SLR without standing up a full meteorological workstation.
Failed validation does not consume balance.
What you can do with it
Forecast snow maps from liquid QPF
Multiply model liquid precipitation by cold, average, and wet SLR scenarios to publish snow accumulation ranges for the public and operations.
Post-storm ratio verification
Divide measured snow board depth by co-located liquid gauge totals to recover the storm snow-to-liquid ratio for after-action logs.
Classroom and homework checks
Let students submit liquid water and a ratio (or snow depth) and verify snow accumulation or inferred SLR against textbook winter-weather problems.
FAQ
What happens if liquid precipitation is negative?
Negative liquid precipitation is not physical and is never converted into a snow depth; invalid input is not billed.
What units should I use for liquid and snow?
Any consistent linear depth unit—millimetres, centimetres, or inches. Do not mix units: the ratio is dimensionless only when both depths share the same unit.
How much snow does 0.5 inches of liquid water make?
At a 10:1 ratio, 0.5 inches of liquid water makes 5 inches of snow; at 12:1 it would be six inches. The calculator applies the ratio you enter, in the same unit as the liquid.
How do I find the snow-to-liquid ratio of a storm?
Enter the measured snow depth and the meltwater collected at the same spot, and leave the ratio empty. Eight inches of snow over 0.8 inches of water gives a ratio of ten.
Is 10:1 the right ratio for every snowfall?
No, it is only a starting point. Colder storms with fluffier snow can run 15:1 or higher, while wet coastal snow can drop toward 6:1. You decide which ratio to apply.
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/earth/snow-to-liquid-ratio \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"liquid_precip":0.5,"snow_to_liquid_ratio":10}'const res = await fetch("https://api.kit.forhosting.com/earth/snow-to-liquid-ratio", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"liquid_precip": 0.5,
"snow_to_liquid_ratio": 10
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/earth/snow-to-liquid-ratio",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"liquid_precip": 0.5,
"snow_to_liquid_ratio": 10
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/earth/snow-to-liquid-ratio", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"liquid_precip":0.5,"snow_to_liquid_ratio":10}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"liquid_precip":0.5,"snow_to_liquid_ratio":10}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/earth/snow-to-liquid-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
{
"liquid_precip": 0.5,
"snow_to_liquid_ratio": 10
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "earth.snow_to_liquid_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. |
Technical notes
What snow-to-liquid ratio means and how accumulation is computed
Negative liquid precipitation never occurs on a physical gauge and is always invalid_input so clients fail fast instead of displaying a nonsense negative snow depth.
Input contract, modes, response fields, and error behaviour
Units are not converted inside this capability: if liquid is in millimetres, express snow in millimetres; if both are inches, the ratio is still snow-over-liquid and remains dimensionless. POST a JSON body with liquid_precip as a required finite number (aliases: liquid, liquid_precipitation, precip, qpf, water_equivalent). Then supply exactly one of the two optional partners: snow_to_liquid_ratio (aliases: slr, ratio, snow_ratio) to run accumulate mode, or snow_depth (aliases: snow, snowfall, accumulation, snow_accum) to run infer_ratio mode. Sending both partners at once is rejected so the API never has to guess which field is authoritative. In accumulate mode the ratio must be a finite positive number; snow depth is returned as liquid_precip multiplied by that ratio, rounded to twelve decimal places for stable cross-runtime goldens. In infer_ratio mode snow_depth must be finite and non-negative, liquid_precip must be strictly greater than zero, and the ratio is snow_depth divided by liquid_precip. The success payload always echoes mode (accumulate or infer_ratio), liquid_precip, snow_to_liquid_ratio, snow_depth, and a short formula string you can display next to the result. Example: liquid_precip 0.5 with snow_to_liquid_ratio 10 yields snow_depth 5 in accumulate mode. Example: liquid_precip 0.4 with snow_depth 6 yields snow_to_liquid_ratio 15 in infer_ratio mode. Negative liquid_precip fails with invalid_input and a message that liquid precipitation cannot be negative; those failures are not billed. Missing both optional partners, a non-positive ratio, negative snow depth, or zero liquid when inferring the ratio also fail as invalid_input.
Where a snow-to-liquid ratio API earns its keep
Broadcast and digital weather products turn liquid QPF grids into snow maps by applying scenario ratios for cold powder, average, and wet snow; a tiny deterministic endpoint lets those pipelines recompute accumulation without embedding ad-hoc spreadsheet logic in every service.
Technical questions
How do I calculate snow accumulation from liquid precipitation?
Send liquid_precip and a positive snow_to_liquid_ratio. The API returns snow_depth = liquid_precip × snow_to_liquid_ratio in the same linear unit as liquid_precip.
How do I find the snow-to-liquid ratio from measurements?
Send liquid_precip (greater than zero) and snow_depth in matching units, and omit the ratio field. The API returns snow_to_liquid_ratio = snow_depth / liquid_precip.
What does the snow-to-liquid 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.