Income Tax Calculator API
Income Tax Calculator is a tool for calculating US federal income tax. It takes your income, filing status, and year to compute your total tax, effective rate, marginal rate, and a full bracket-by-bracket breakdown.
The Income Tax Calculator API provides reliable and fast access to income tax calculator data through a simple REST interface. Built for developers who need consistent, high-quality results with minimal setup time.
To use Income Tax Calculator, you need an API key. You can get one by creating a free account and visiting your dashboard.
GET Endpoint
https://api.apiverve.com/v1/incometaxcalculatorCode Examples
Here are examples of how to call the Income Tax Calculator API in different programming languages:
curl -X GET \
"https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600" \
-H "X-API-Key: your_api_key_here"const response = await fetch('https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600', {
method: 'GET',
headers: {
'X-API-Key': 'your_api_key_here',
'Content-Type': 'application/json'
}
});
const data = await response.json();
console.log(data);import requests
headers = {
'X-API-Key': 'your_api_key_here',
'Content-Type': 'application/json'
}
response = requests.get('https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600', headers=headers)
data = response.json()
print(data)const https = require('https');
const url = require('url');
const options = {
method: 'GET',
headers: {
'X-API-Key': 'your_api_key_here',
'Content-Type': 'application/json'
}
};
const req = https.request('https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600', options, (res) => {
let data = '';
res.on('data', (chunk) => data += chunk);
res.on('end', () => console.log(JSON.parse(data)));
});
req.end();<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
curl_setopt($ch, CURLOPT_HTTPHEADER, [
'X-API-Key: your_api_key_here',
'Content-Type: application/json'
]);
$response = curl_exec($ch);
curl_close($ch);
$data = json_decode($response, true);
print_r($data);
?>package main
import (
"fmt"
"io"
"net/http"
)
func main() {
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600", nil)
req.Header.Set("X-API-Key", "your_api_key_here")
req.Header.Set("Content-Type", "application/json")
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
panic(err)
}
defer resp.Body.Close()
body, _ := io.ReadAll(resp.Body)
fmt.Println(string(body))
}require 'net/http'
require 'json'
uri = URI('https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
request = Net::HTTP::Get.new(uri)
request['X-API-Key'] = 'your_api_key_here'
request['Content-Type'] = 'application/json'
response = http.request(request)
puts JSON.pretty_generate(JSON.parse(response.body))using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
class Program
{
static async Task Main(string[] args)
{
using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key", "your_api_key_here");
var response = await client.GetAsync("https://api.apiverve.com/v1/incometaxcalculator?income=85000&rate=22&deduction=14600");
response.EnsureSuccessStatusCode();
var responseBody = await response.Content.ReadAsStringAsync();
Console.WriteLine(responseBody);
}
}Authentication
The Income Tax Calculator API requires authentication via API key. Include your API key in the request header:
X-API-Key: your_api_key_hereInteractive API Playground
Test the Income Tax Calculator API directly in your browser with live requests and responses.
Parameters
The Income Tax Calculator API supports multiple query options. Use one of the following:
Option 1: Calculate Tax with Custom Rate
| Parameter | Type | Required | Description | Default | Example |
|---|---|---|---|---|---|
income | number | required | Gross annual income in USD Range: min: 0 | - | |
rate | number | required | Tax rate as a percentage (e.g., 22 for 22%) Range: 0 - 100 | - | |
deduction | number | optional | Optional deduction amount to subtract from income before calculating tax Range: min: 0 | - |
Option 2: Calculate US Federal Income Tax
| Parameter | Type | Required | Description | Default | Example |
|---|---|---|---|---|---|
income | number | required | Gross annual income in USD Range: min: 0 | - | |
filing_status | string | required | Filing status | - | |
yearPremium | integer | optional | The tax year to use for brackets. Defaults to the previous year. | - |
Response
The Income Tax Calculator API returns responses in JSON, XML, YAML, and CSV formats:
Example Responses
{
"status": "ok",
"error": null,
"data": {
"year": 2025,
"filing_status": "single",
"income": 85000,
"standardDeduction": 15000,
"taxableIncome": 70000,
"totalTax": 10852.5,
"effectiveRate": "12.77%",
"marginalRate": "22%",
"incomeAfterTax": 74147.5,
"monthlyTax": 904.38,
"monthlyIncome": 6178.96,
"brackets": [
{
"rate": 0.1,
"ratePercent": "10.0%",
"rangeMin": 0,
"rangeMax": 11925,
"taxableAmount": 11926,
"taxAmount": 1192.6
},
{
"rate": 0.12,
"ratePercent": "12.0%",
"rangeMin": 11926,
"rangeMax": 48475,
"taxableAmount": 36550,
"taxAmount": 4386
},
{
"rate": 0.22,
"ratePercent": "22.0%",
"rangeMin": 48476,
"rangeMax": 103350,
"taxableAmount": 21524,
"taxAmount": 4735.28
}
]
}
}<?xml version="1.0" encoding="UTF-8"?>
<response>
<status>ok</status>
<error xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
<data>
<year>2025</year>
<filing_status>single</filing_status>
<income>85000</income>
<standardDeduction>15000</standardDeduction>
<taxableIncome>70000</taxableIncome>
<totalTax>10852.5</totalTax>
<effectiveRate>12.77%</effectiveRate>
<marginalRate>22%</marginalRate>
<incomeAfterTax>74147.5</incomeAfterTax>
<monthlyTax>904.38</monthlyTax>
<monthlyIncome>6178.96</monthlyIncome>
<brackets>
<bracket>
<rate>0.1</rate>
<ratePercent>10.0%</ratePercent>
<rangeMin>0</rangeMin>
<rangeMax>11925</rangeMax>
<taxableAmount>11926</taxableAmount>
<taxAmount>1192.6</taxAmount>
</bracket>
<bracket>
<rate>0.12</rate>
<ratePercent>12.0%</ratePercent>
<rangeMin>11926</rangeMin>
<rangeMax>48475</rangeMax>
<taxableAmount>36550</taxableAmount>
<taxAmount>4386</taxAmount>
</bracket>
<bracket>
<rate>0.22</rate>
<ratePercent>22.0%</ratePercent>
<rangeMin>48476</rangeMin>
<rangeMax>103350</rangeMax>
<taxableAmount>21524</taxableAmount>
<taxAmount>4735.28</taxAmount>
</bracket>
</brackets>
</data>
</response>
status: ok
error: null
data:
year: 2025
filing_status: single
income: 85000
standardDeduction: 15000
taxableIncome: 70000
totalTax: 10852.5
effectiveRate: 12.77%
marginalRate: 22%
incomeAfterTax: 74147.5
monthlyTax: 904.38
monthlyIncome: 6178.96
brackets:
- rate: 0.1
ratePercent: 10.0%
rangeMin: 0
rangeMax: 11925
taxableAmount: 11926
taxAmount: 1192.6
- rate: 0.12
ratePercent: 12.0%
rangeMin: 11926
rangeMax: 48475
taxableAmount: 36550
taxAmount: 4386
- rate: 0.22
ratePercent: 22.0%
rangeMin: 48476
rangeMax: 103350
taxableAmount: 21524
taxAmount: 4735.28
| key | value |
|---|---|
| year | 2025 |
| filing_status | single |
| income | 85000 |
| standardDeduction | 15000 |
| taxableIncome | 70000 |
| totalTax | 10852.5 |
| effectiveRate | 12.77% |
| marginalRate | 22% |
| incomeAfterTax | 74147.5 |
| monthlyTax | 904.38 |
| monthlyIncome | 6178.96 |
| brackets | [{rate:0.1,ratePercent:10.0%,rangeMin:0,rangeMax:11925,taxableAmount:11926,taxAmount:1192.6},{rate:0.12,ratePercent:12.0%,rangeMin:11926,rangeMax:48475,taxableAmount:36550,taxAmount:4386},{rate:0.22,ratePercent:22.0%,rangeMin:48476,rangeMax:103350,taxableAmount:21524,taxAmount:4735.28}] |
Response Structure
All API responses follow a consistent structure with the following fields:
| Field | Type | Description | Example |
|---|---|---|---|
status | string | Indicates whether the request was successful ("ok") or failed ("error") | ok |
error | string | null | Contains error message if status is "error", otherwise null | null |
data | object | null | Contains the API response data if successful, otherwise null | {...} |
Learn more about response formats →
Response Data Fields
When the request is successful, the data object contains the following fields:
| Field | Type | Sample Value | Description |
|---|---|---|---|
year | number | Tax year used for calculation | |
filing_status | string | Filing status used | |
income | number | Original gross income provided | |
standardDeduction | number | Standard deduction applied based on filing status | |
taxableIncome | number | Income after standard deduction | |
totalTax | number | Total federal tax owed | |
effectiveRate | string | Effective tax rate as percentage | |
marginalRate | string | Marginal tax rate (highest bracket) | |
incomeAfterTax | number | Take-home income after tax | |
monthlyTax | number | Monthly tax amount (totalTax / 12) | |
monthlyIncome | number | Monthly take-home income (incomeAfterTax / 12) | |
| [ ] Array items: | array[3] | Detailed breakdown of tax by bracket | |
â”” rate | number | Tax rate used for calculation (as percentage) | |
â”” ratePercent | string | - | |
â”” rangeMin | number | - | |
â”” rangeMax | number | - | |
â”” taxableAmount | number | - | |
â”” taxAmount | number | - |
Headers
Required and optional headers for Income Tax Calculator API requests:
| Header Name | Required | Example Value | Description |
|---|---|---|---|
X-API-Key | required | your_api_key_here | Your APIVerve API key. Found in your dashboard under API Keys. |
Accept | optional | application/json | Specify response format: application/json (default), application/xml, or application/yaml |
User-Agent | optional | MyApp/1.0 | Identifies your application for analytics and debugging purposes |
X-Request-ID | optional | req_123456789 | Custom request identifier for tracking and debugging requests |
Cache-Control | optional | no-cache | Control caching behavior for the request and response |
GraphQL AccessALPHA
Access Income Tax Calculator through GraphQL to combine it with other API calls in a single request. Query only the income tax calculator data you need with precise field selection, and orchestrate complex data fetching workflows.
Credit Cost: Each API called in your GraphQL query consumes its standard credit cost.
POST https://api.apiverve.com/v1/graphqlquery {
incometaxcalculator(
input: {
income: 85000
rate: 22
deduction: 14600
}
) {
year
filing_status
income
standardDeduction
taxableIncome
totalTax
effectiveRate
marginalRate
incomeAfterTax
monthlyTax
monthlyIncome
brackets
}
}Note: Authentication is handled via the x-api-key header in your GraphQL request, not as a query parameter.
CORS Support
The Income Tax Calculator API supports Cross-Origin Resource Sharing (CORS) with wildcard configuration, allowing you to call Income Tax Calculator directly from browser-based applications without proxy servers.
| CORS Header | Value | Description |
|---|---|---|
Access-Control-Allow-Origin | * | Accepts requests from any origin |
Access-Control-Allow-Methods | * | Accepts any HTTP method |
Access-Control-Allow-Headers | * | Accepts any request headers |
Browser Usage: You can call Income Tax Calculator directly from JavaScript running in the browser without encountering CORS errors. No proxy server or additional configuration needed.
Rate Limiting
Income Tax Calculator API requests are subject to rate limiting based on your subscription plan. These limits ensure fair usage and maintain service quality for all Income Tax Calculator users.
| Plan | Rate Limit | Description |
|---|---|---|
| Free | 5 requests/min | Hard rate limit enforced - exceeding will return 429 errors |
| Starter | No Limit | Production ready - standard traffic priority |
| Pro | No Limit | Production ready - preferred traffic priority |
| Mega | No Limit | Production ready - highest traffic priority |
Learn more about rate limiting →
Rate Limit Headers
When rate limits apply, each Income Tax Calculator response includes headers to help you track your usage:
| Header | Description |
|---|---|
X-RateLimit-Limit | Maximum number of requests allowed per time window |
X-RateLimit-Remaining | Number of requests remaining in the current window |
X-RateLimit-Reset | Unix timestamp when the rate limit window resets |
Handling Rate Limits
Free Plan: When you exceed your rate limit, Income Tax Calculator returns a 429 Too Many Requests status code. Your application should implement appropriate backoff logic to handle this gracefully.
Paid Plans: No rate limiting or throttling applied. All paid plans (Starter, Pro, Mega) are production-ready.
Best Practices for Income Tax Calculator:
- Monitor the rate limit headers to track your Income Tax Calculator usage (Free plan only)
- Cache income tax calculator responses where appropriate to reduce API calls
- Upgrade to Pro or Mega for guaranteed no-throttle Income Tax Calculator performance
Note: Income Tax Calculator rate limits are separate from credit consumption. You may have credits remaining but still hit rate limits when using Income Tax Calculator on Free tier.
Error Codes
The Income Tax Calculator API uses standard HTTP status codes to indicate success or failure:
| Code | Message | Description | Solution |
|---|---|---|---|
200 | OK | Request successful, data returned | No action needed - request was successful |
400 | Bad Request | Invalid request parameters or malformed request | Check required parameters and ensure values match expected formats |
401 | Unauthorized | Missing or invalid API key | Include x-api-key header with valid API key from dashboard |
403 | Forbidden | API key lacks permission or insufficient credits | Check credit balance in dashboard or upgrade plan |
429 | Too Many Requests | Rate limit exceeded (Free: 5 req/min) | Implement request throttling or upgrade to paid plan |
500 | Internal Server Error | Server error occurred | Retry request after a few seconds, contact support if persists |
503 | Service Unavailable | API temporarily unavailable | Wait and retry, check status page for maintenance updates |
Learn more about error handling →
Need help? Contact support with your X-Request-ID for assistance.
Integrate Income Tax Calculator with SDKs
Get started quickly with official Income Tax Calculator SDKs for your preferred language. Each library handles authentication, request formatting, and error handling automatically.
Available for Node.js, Python, C#/.NET, and Android/Java. All SDKs are open source and regularly updated.
Integrate Income Tax Calculator with No-Code API Tools
Connect the Income Tax Calculator API to your favorite automation platform without writing code. Build workflows that leverage income tax calculator data across thousands of apps.





All platforms use your same API key to access Income Tax Calculator. Visit our integrations hub for step-by-step setup guides.
Frequently Asked Questions
How do I get an API key for Income Tax Calculator?
How many credits does Income Tax Calculator cost?
Each successful Income Tax Calculator API call consumes credits based on plan tier. Check the pricing section above for the exact credit cost. Failed requests and errors don't consume credits, so you only pay for successful income tax calculator lookups.
Can I use Income Tax Calculator in production?
The free plan is for testing and development only. For production use of Income Tax Calculator, upgrade to a paid plan (Starter, Pro, or Mega) which includes commercial use rights, no attribution requirements, and guaranteed uptime SLAs. All paid plans are production-ready.
Can I use Income Tax Calculator from a browser?
What happens if I exceed my Income Tax Calculator credit limit?
When you reach your monthly credit limit, Income Tax Calculator API requests will return an error until you upgrade your plan or wait for the next billing cycle. You'll receive notifications at 80% and 95% usage to give you time to upgrade if needed.



