Ratio Calculator
What Is This?
Ratio Calculator simplifies, scales, and compares ratios. It finds equivalent ratios, solves proportions, converts ratios to fractions/decimals/percentages, and helps with design aspect ratios, recipe scaling, and mathematical proportion problems.
Input
Formula: A:B = ?
How to Use
Enter a ratio like 16:9 or values as A:B. The tool simplifies it to lowest terms, shows equivalent ratios, and converts to fraction and decimal forms. For scaling, enter a target value for one side to find the proportional other side.
Deep Dive
The Golden Ratio (phi, approximately 1.618:1) has fascinated mathematicians since ancient Greece. Two quantities are in the golden ratio when their ratio equals the ratio of their sum to the larger quantity: (a+b)/a = a/b. It appears in the Fibonacci sequence (each consecutive pair's ratio approaches phi), sunflower seed spirals (137.5-degree divergence angle), and the proportions of a regular pentagon.
In design and media, aspect ratios define the relationship between width and height. The most common screen ratios tell a story of technological evolution: 4:3 (1.33:1) dominated early television and CRT monitors. 16:9 (1.78:1) became the HDTV standard in the 1990s, chosen as a mathematical compromise between 4:3 and the wider cinema formats. 21:9 (2.33:1) ultrawide monitors approximate the cinema standard. Film uses 2.39:1 (CinemaScope/anamorphic widescreen) and 1.85:1 (standard US theatrical).
Mobile devices introduced new ratios: 9:16 (vertical video), 19.5:9 (modern smartphones like iPhone), and 20:9 (many Android devices). Instagram uses 1:1 (square), 4:5 (portrait), and 1.91:1 (landscape). Understanding these ratios is essential for responsive design - a 16:9 image cropped to 1:1 loses 44% of its width.
In cooking, scaling ratios preserves flavor balance. Baker's percentages express all ingredients as a percentage of flour weight, making it trivial to scale: 60% hydration bread uses 600g water per 1000g flour, regardless of batch size.
Examples
- Simplify the ratio 1920:1080 to its lowest terms: 16:9 (dividing both by GCD of 120)
- Scale a recipe from 4 servings to 6: multiply all ingredient ratios by 1.5
- Find the missing value in a proportion: if 3:5 = x:20, then x = 12
Install Toolypet MCP Server
Add Toolypet tools to your AI agent with a single command. Works with Claude Desktop, Claude Code, Cursor, and any MCP-compatible client.
Quick Start
npx -y @toolypet/mcp-server@latest
MCP Client Configuration
{
"mcpServers": {
"toolypet": {
"command": "npx",
"args": [
"-y",
"@toolypet/mcp-server@latest"
]
}
}
}Tool Name:
mcp__toolypet__ratio_calculatorExample Prompt
Use mcp__toolypet__ratio_calculator to ...
Frequently Asked Questions
- What is the Golden Ratio?
- The Golden Ratio (phi = 1.618...) is an irrational number where a/b = (a+b)/a. It appears in nature (spiral shells, flower petals), art (Renaissance compositions), and architecture (Parthenon proportions), though some claims are debated.
- How do I simplify a ratio?
- Divide both numbers by their Greatest Common Divisor (GCD). For 1920:1080, the GCD is 120, giving 16:9. The calculator finds the GCD automatically and shows the simplified form.
- What are common screen aspect ratios?
- 4:3 for classic TV/monitors, 16:9 for HDTV and most screens, 21:9 for ultrawide monitors, 9:16 for vertical video, and 1:1 for square social media content. Film uses 1.85:1 and 2.39:1.
- How do I convert a ratio to a percentage?
- Divide the first number by the sum of both numbers and multiply by 100. A 3:2 ratio means 3/(3+2) * 100 = 60% for the first part and 40% for the second.
- What is the difference between a ratio and a fraction?
- A ratio (3:2) compares two quantities to each other. A fraction (3/5) represents a part of the whole. The ratio 3:2 means 3 parts to 2 parts; as fractions, that is 3/5 and 2/5 of the total.
- How do I use this tool in Claude/Cursor?
- You can use this tool via MCP. Add the Toolypet MCP server to your AI agent configuration with 'npx -y @toolypet/mcp-server@latest'. Then ask your AI to use mcp__toolypet__ratio_calculator with your parameters.
- What is MCP and why does Toolypet support it?
- MCP (Model Context Protocol) is an open standard that lets AI agents like Claude and Cursor use external tools. Toolypet supports MCP so you can use all 65+ tools both in the browser and through AI agents, making calculations and operations seamlessly integrated into your AI workflow.