ForHosting KIT · Unit converters

Geologic rate converter

Put a geologic rate into the unit your source uses: 10 mm per year is 1 cm per year or 0.3937 inches per year. Choose how many decimals you want, and the rounding is applied once, at the end. Free in your browser.

Free
Runs in your browser
No sign-up
Your data stays on your device

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Worked example

If you enter

Mm per yr: 10
Decimal places: 4

You get

Cm per yr: 1
M per Myr: 10
Km per Myr: 0.01
In per yr: 0.3937

Convert geologic rates among mm/yr, cm/yr, m/Myr, km/Myr and in/yr. Search intent: mm per year to inches geologic. No network calls, no random seeds, and no server state are required for a correct answer. Failed jobs are not

Slow processes, measured per year

Geologic rates describe how fast the ground changes: how far a fault slips, how quickly a coastline rises or how much sediment settles on a lake bed each year. Field reports and papers rarely agree on the unit. One study gives millimetres per year, another centimetres, and older American sources use inches. This converter takes the rate in the unit you have and shows it in the others, so you can compare figures from different sources side by side. Every value is first expressed in millimetres per year: centimetres are that number divided by 10, and inches are that number divided by 25.4, because one inch is exactly 25.4 millimetres.

Rounding and the usual slips

You choose how many decimals you want, and the rounding is applied only once, to the final figure, with halves rounded up. Rounding at every intermediate step would let small errors pile up. With four decimals, 10 millimetres per year becomes 1 centimetre per year and 0.3937 inches per year. The most common mistake is moving the decimal point the wrong way between millimetres and centimetres; the second is forgetting that an inch is 25.4 millimetres, not a round number. Values that are not numbers are rejected before any calculation instead of being guessed.

When to use it

Use when the search intent matches this tool. Convert geologic rates among mm/yr, cm/yr, m/Myr, km/Myr and in/yr. No network calls, no random seeds, and no server state are required for a correct answer.

Failed jobs are not billed. Landings target the stated search intent with precise keywords. Prefer explicit units and ranges over silent coercion of bad types.

When a field is optional, defaults are documented in params and echoed in the output.

FAQ

Locales?

EN-only delivery; Nitro hydrates the other seven languages.

How do I convert millimetres per year to inches per year?

Divide the millimetres per year by 25.4, since one inch is exactly 25.4 millimetres. A rate of 10 mm per year is therefore about 0.3937 inches per year when rounded to four decimals.

How many centimetres per year is 10 mm per year?

Exactly 1 centimetre per year. Divide millimetres by 10 to get centimetres, or multiply centimetres by 10 to go back to millimetres.

How many decimals does the result show?

As many as you ask for. The converter rounds once, on the final figure, with halves rounded up, so 10 mm per year shows as 0.3937 inches per year at four decimals.

Can I start from inches or centimetres per year?

Yes. Enter the rate in whichever unit your source uses. The converter first expresses it in millimetres per year and then shows it in the other units.

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

POSThttps://api.kit.forhosting.com/conv/geologic-rate

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/geologic-rate \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"mm_per_yr":10}'

const res = await fetch("https://api.kit.forhosting.com/conv/geologic-rate", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "mm_per_yr": 10
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/conv/geologic-rate",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "mm_per_yr": 10
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/geologic-rate", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"mm_per_yr":10}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"mm_per_yr":10}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/geologic-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

{
  "mm_per_yr": 10
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "conv.geologic_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

Per request$0.002

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 calculator is free in the browser, deterministic, and identical in the API path. Inputs are validated before any arithmetic so invalid payloads fail with invalid_input. Half-up rounding is applied once from raw IEEE results when decimals are requested. Use the same JSON contract from spreadsheets, CMS hooks, automation, or teaching demos.

How it works

No network calls, no random seeds, and no server state are required for a correct answer. Failed jobs are not billed. Landings target the stated search intent with precise keywords. Prefer explicit units and ranges over silent coercion of bad types. When a field is optional, defaults are documented in params and echoed in the output. Convert geologic rates among mm/yr, cm/yr, m/Myr, km/Myr and in/yr. 1 m/Myr = 1 mm/yr; 1 km/Myr = 1000 mm/yr; 1 in = 25.4 mm. The calculator is free in the browser, deterministic, and identical in the API path. Inputs are validated before any arithmetic so invalid payloads fail with invalid_input. Half-up rounding is applied once from raw IEEE results when decimals are requested. Use the same JSON contract from spreadsheets, CMS hooks, automation, or teaching demos.

Inputs, limits and rounding

Outputs echo inputs for logging. No network calls, no random seeds, and no server state are required for a correct answer. Failed jobs are not billed. Landings target the stated search intent with precise keywords. Prefer explicit units and ranges over silent coercion of bad types. When a field is optional, defaults are documented in params and echoed in the output. Provide required JSON fields. Optional decimals use half-up once from raw IEEE values. Invalid types or ranges raise invalid_input. The calculator is free in the browser, deterministic, and identical in the API path. Inputs are validated before any arithmetic so invalid payloads fail with invalid_input. Half-up rounding is applied once from raw IEEE results when decimals are requested. Use the same JSON contract from spreadsheets, CMS hooks, automation, or teaching demos.

When to use it

Integration use cases

Quick check

Use the free widget to verify a formula before production.

Automation

Call the API with the same JSON contract from scripts or CMS.

Teaching

Show pinned golden examples without proprietary software.

Technical questions

Is the browser widget free?

Yes. Tier A is free client-side with the same core as the API.

Does it use the network?

No. Computation is local and deterministic.

What on bad input?

invalid_input is thrown; failed jobs are not billed.

API compatible?

Yes — same JSON fields as params.json.

Read the full KIT documentation →

Run — free

Worked example

Slow processes, measured per year

Rounding and the usual slips

When to use it

FAQ

Related tools

For developers — API access

API endpoint

Call it from your stack

Example request

Example response

Pricing

Errors

Technical notes

How it works

Inputs, limits and rounding

When to use it

Integration use cases

Quick check

Automation

Teaching

Technical questions

thank you