ForHosting KIT · Developer Utilities

Charles's law final volume calculator

This Charles's law final volume calculator finds the final gas volume when temperature changes at constant pressure.

● BetaFree · in your browser

Use it from WebAPIEmailTelegramApp soon

You supply the initial volume V1, the initial absolute temperature T1, and the new absolute temperature T2; the engine returns the final volume V2 from the classical proportion V1 over T1 equals V2 over T2, which rearranges to V2 equals V1 times T2 over T1. That identity is Charles's law: for a fixed amount of ideal gas held at constant pressure, volume scales linearly with absolute temperature. Worked checks include V1 equals two, T1 equals three hundred, T2 equals six hundred yielding V2 equals four, and V1 equals five, T1 equals two hundred fifty, T2 equals three hundred yielding V2 equals six. Temperatures must be absolute (typically Kelvin); zero initial temperature is rejected because the rearrange divides by T1. The path is pure finite arithmetic with no network calls, no sampling, and no date-dependent shortcuts. Use it free in the browser for homework, lab prep, and gas-law drills, or call the API at $0.002 per successful request when you need reproducible final-volume fixtures in CI, tutoring software, or teaching demos.

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 do I use this capability?

Complete the fields above and run it on this page. The form highlights anything that needs attention.

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/chem/charles-final-volume

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/chem/charles-final-volume \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"V1":2,"T1":300,"T2":600}'

const res = await fetch("https://api.kit.forhosting.com/chem/charles-final-volume", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "V1": 2,
    "T1": 300,
    "T2": 600
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/chem/charles-final-volume",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "V1": 2,
    "T1": 300,
    "T2": 600
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/chem/charles-final-volume", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"V1":2,"T1":300,"T2":600}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"V1":2,"T1":300,"T2":600}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/chem/charles-final-volume", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "V1": 2,
  "T1": 300,
  "T2": 600
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "chem.charles_final_volume",
  "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.

Limits

max_abs_value 1000000000000000

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.

Read the full KIT documentation →