ForHosting KIT · Developer Utilities

Add sales tax calculator

An add sales tax calculator answers the checkout question every invoice, cart, and quote must settle: if this line is still pre-tax, and the applicable rate is this many percent, how much tax do I add and what does the customer pay as the gross amount?

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Merchants, bookkeepers, marketplace sellers, and students all start from a net subtotal they already know—the shelf price, the service fee, the quote line—and need a single forward pass that applies the rate as a percentage, not as a reverse extract from a tax-inclusive ticket. This tool takes that pre-tax price and the rate, computes tax amount as price times rate over one hundred, then adds the rounded tax to the price to produce the gross total. Zero percent is a valid exempt line. A negative rate is rejected instead of being treated as a rebate. The same pure module powers the free browser widget and the prepaid API, so a check you run on the landing page matches a script you run later, down to the cent.

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/finance/sales-tax-add

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/finance/sales-tax-add \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"price":100,"tax_rate":8.25}'

const res = await fetch("https://api.kit.forhosting.com/finance/sales-tax-add", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "price": 100,
    "tax_rate": 8.25
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/finance/sales-tax-add",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "price": 100,
    "tax_rate": 8.25
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/finance/sales-tax-add", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"price":100,"tax_rate":8.25}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"price":100,"tax_rate":8.25}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/finance/sales-tax-add", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "price": 100,
  "tax_rate": 8.25
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "finance.sales_tax_add",
  "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`	1000000000000
`max_tax_rate_percent`	1000

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 →