Tip Calculator API: The Complete Guide

Need to calculate tips in your application? This guide covers everything you need to know about tip calculations via API, including tip percentages, bill splitting, and implementation examples in multiple languages.

What is a Tip Calculator?

A tip calculator helps determine the appropriate gratuity amount based on the bill total and desired tip percentage. It can also split the bill among multiple people, making it easier to handle group dining situations.

Tip calculators are essential for restaurant apps, expense tracking tools, and personal finance applications.

Standard Tip Percentages

Common tip percentages in the United States:

Using the Tip Calculator API

TinyFn provides a simple endpoint for tip calculations:

GET https://api.tinyfn.io/v1/math/tip
Headers: X-API-Key: your-api-key

{
  "bill_amount": 85.50,
  "tip_percentage": 20,
  "tip_amount": 17.10,
  "total": 102.60,
  "split_count": 4,
  "per_person": 25.65
}

Parameters

Code Examples

JavaScript / Node.js

const response = await fetch(
  'https://api.tinyfn.io/v1/math/tip?bill_amount=85.50&tip_percentage=20&split_count=4',
  { headers: { 'X-API-Key': 'your-api-key' } }
);
const data = await response.json();
console.log(data.tip_amount); // 17.10
console.log(data.per_person); // 25.65

Python

import requests

response = requests.get(
    'https://api.tinyfn.io/v1/math/tip',
    params={
        'bill_amount': 85.50,
        'tip_percentage': 20,
        'split_count': 4
    },
    headers={'X-API-Key': 'your-api-key'}
)
data = response.json()
print(data['per_person'])  # 25.65

cURL

curl "https://api.tinyfn.io/v1/math/tip?bill_amount=85.50&tip_percentage=20&split_count=4" \
  -H "X-API-Key: your-api-key"

Common Use Cases

• Restaurant Apps: Calculate tips at checkout
• Expense Tracking: Log meal expenses with tips
• Bill Splitting Apps: Divide costs among groups
• Point of Sale Systems: Suggest tip amounts
• Travel Apps: Help tourists with local tipping customs

Best Practices

1. Offer presets: Provide common tip percentages (15%, 18%, 20%, 25%)
2. Round options: Offer to round up to nearest dollar
3. Show breakdown: Display tip amount, total, and per-person clearly
4. Consider locale: Adjust defaults based on user's region

Use via MCP

Your AI agent can call this tool directly via Model Context Protocol — no HTTP code needed. Add TinyFn to Claude Desktop, Cursor, or any MCP client:

{
  "mcpServers": {
    "tinyfn-math": {
      "url": "https://api.tinyfn.io/mcp/math/",
      "headers": {
        "X-API-Key": "your-api-key"
      }
    }
  }
}

See all math tools available via MCP in our Math MCP Tools for AI Agents guide.