ForHosting KIT · Developer Utilities

Sodium deficit calculator

The sodium deficit calculator estimates how many milliequivalents of sodium would be needed to move serum sodium from a current laboratory value to a chosen target, using a sex-specific total-body-water fraction times body weight in kilograms.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Clinicians in training, nursing students, and health-software teams use that identity when teaching hyponatremia replacement, reviewing electrolyte worksheets, or wiring educational calculators into apps. You send current serum sodium, target sodium, weight, and sex; the tool returns the deficit in milliequivalents together with the implied total body water and the sodium gap. Current sodium that is missing, zero, negative, or not a finite number fails with invalid_input and is not billed. The same pure JavaScript module powers the free browser widget and the prepaid API at $0.002 per successful item. Results are educational estimates only and do not replace serial laboratory monitoring, fluid choice, or professional medical advice.

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 is the sodium deficit calculated?

sodium_deficit = TBW × (target_sodium − sodium), with TBW = 0.6 × weight kg for males and 0.5 × weight kg for females. The result is milliequivalents (mEq). The response also returns tbw, tbw_fraction, and delta_sodium.

What fields are required?

Four required fields: sodium (current serum Na in mEq/L, must be a positive number), target_sodium (desired Na in mEq/L), weight (kilograms), and sex (male or female). Missing fields return invalid_input and are not billed.

What happens if current serum sodium is zero or negative?

The request fails with invalid_input. Current sodium that is not a positive number is not a valid laboratory input for this formula and is not charged.

What does the sodium deficit calculator cost?

The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.

Does this replace medical advice or use Watson total body water?

No. Results are educational estimates using adult teaching fractions 0.6 and 0.5, not the Watson equations. People with sodium disorders should follow professional guidance, not this calculator alone.

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/health/sodium-deficit

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/health/sodium-deficit \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"items":["valor-1","valor-2"]}'

const res = await fetch("https://api.kit.forhosting.com/health/sodium-deficit", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "items": [
      "valor-1",
      "valor-2"
    ]
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/health/sodium-deficit",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "items": [
        "valor-1",
        "valor-2"
    ]
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/sodium-deficit", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"items":["valor-1","valor-2"]}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"items":["valor-1","valor-2"]}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/sodium-deficit", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "items": [
    "valor-1",
    "valor-2"
  ]
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "health.sodium_deficit",
  "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 →