ForHosting KIT · Developer Utilities

Aircraft weight and balance calculator

Every takeoff starts with a weight and balance check: empty aircraft, crew, passengers, fuel, and baggage each sit at a known arm from the datum, and the resulting center of gravity must stay inside the certified envelope.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

This aircraft weight and balance calculator accepts a list of stations with weight and arm, multiplies each pair into a moment, sums weight and moment, and returns CG as total moment divided by total weight. Optional maximum gross weight and forward/aft CG limits report whether the loading is legal on paper before you walk out to the ramp. The same pure arithmetic powers the free browser widget and the API path, so flight-school drills, dispatch scripts, and personal logbook tools never disagree on a four-station Cessna-style example. Failed validation is not billed; successful calls use the published $0.002 base price with no model tokens and no outbound network.

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/travel/weight-and-balance

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/travel/weight-and-balance \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"stations":[{"name":"Empty weight","weight":1500,"arm":85},{"name":"Front seats","weight":340,"arm":85},{"name":"Fuel","weight":240,"arm":95},{"name":"Baggage","weight":50,"arm":140}]}'

const res = await fetch("https://api.kit.forhosting.com/travel/weight-and-balance", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "stations": [
      {
        "name": "Empty weight",
        "weight": 1500,
        "arm": 85
      },
      {
        "name": "Front seats",
        "weight": 340,
        "arm": 85
      },
      {
        "name": "Fuel",
        "weight": 240,
        "arm": 95
      },
      {
        "name": "Baggage",
        "weight": 50,
        "arm": 140
      }
    ]
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/travel/weight-and-balance",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "stations": [
        {
            "name": "Empty weight",
            "weight": 1500,
            "arm": 85
        },
        {
            "name": "Front seats",
            "weight": 340,
            "arm": 85
        },
        {
            "name": "Fuel",
            "weight": 240,
            "arm": 95
        },
        {
            "name": "Baggage",
            "weight": 50,
            "arm": 140
        }
    ]
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/travel/weight-and-balance", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"stations":[{"name":"Empty weight","weight":1500,"arm":85},{"name":"Front seats","weight":340,"arm":85},{"name":"Fuel","weight":240,"arm":95},{"name":"Baggage","weight":50,"arm":140}]}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"stations":[{"name":"Empty weight","weight":1500,"arm":85},{"name":"Front seats","weight":340,"arm":85},{"name":"Fuel","weight":240,"arm":95},{"name":"Baggage","weight":50,"arm":140}]}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/travel/weight-and-balance", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "stations": [
    {
      "name": "Empty weight",
      "weight": 1500,
      "arm": 85
    },
    {
      "name": "Front seats",
      "weight": 340,
      "arm": 85
    },
    {
      "name": "Fuel",
      "weight": 240,
      "arm": 95
    },
    {
      "name": "Baggage",
      "weight": 50,
      "arm": 140
    }
  ]
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "travel.weight_and_balance",
  "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.

Read the full KIT documentation →