# Units and Conversions

Exact unit, cooking, fuel, data-size, duration, number and base conversions, plus heat index and wind chill.

## How to pay

Machine-payable over x402. USDC on: Base (eip155:8453), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), Polygon (eip155:137), Arbitrum One (eip155:42161).
No accounts. No API keys. No signup. The paying wallet is the account.

## Machine-readable

- OpenAPI: https://units-convert.x402tookit.com/openapi.json
- x402 manifest: https://units-convert.x402tookit.com/.well-known/x402
- Catalog (free): https://units-convert.x402tookit.com/catalog
- Health (free): https://units-convert.x402tookit.com/health
- Uptime (free): https://units-convert.x402tookit.com/uptime

## Endpoints (9)

### GET /base-convert — $0.02
Convert a number between bases 2 to 36 exactly (binary, octal, decimal, hex), with big-integer precision.
Params: value: string, from_base?: integer, to_base?: integer
Example: https://units-convert.x402tookit.com/base-convert?value=255&from_base=10&to_base=2

### GET /cooking-convert — $0.02
Convert cooking measures: cups, tablespoons, teaspoons, ml, ounces and grams, with weight for flour, sugar, butter and more.
Params: value: number, from: string, to: string, ingredient?: string
Example: https://units-convert.x402tookit.com/cooking-convert?value=2&from=cup&to=g&ingredient=flour

### GET /data-size — $0.02
Convert data sizes between bytes, KB/MB/GB/TB (decimal) and KiB/MiB/GiB/TiB (binary), and the time to transfer at a speed.
Params: value: number, unit: string, speed_mbps?: number
Example: https://units-convert.x402tookit.com/data-size?value=1.5&unit=gib&speed_mbps=100

### GET /duration-format — $0.02
Turn seconds into a readable duration (2 h 5 min) or parse one like '1d 3h 20m' back into seconds, minutes and hours.
Params: seconds?: number, text?: string
Example: https://units-convert.x402tookit.com/duration-format?seconds=93784

### GET /feels-like — $0.02
Apparent temperature: heat index from temperature and humidity, wind chill from temperature and wind, with a danger category.
Params: temp_f: number, humidity_pct?: number, wind_mph?: number
Example: https://units-convert.x402tookit.com/feels-like?temp_f=90&humidity_pct=70&wind_mph=5

### GET /fuel-economy — $0.02
Convert fuel economy between US mpg, UK mpg, km per litre and litres per 100 km, with optional trip fuel and cost.
Params: value: number, unit: string, distance_miles?: number, price_per_gallon_us?: number
Example: https://units-convert.x402tookit.com/fuel-economy?value=32&unit=mpg_us&distance_miles=300&price_per_gallon_us=3.5

### GET /number-words — $0.02
Write a whole number in English words (cardinal and ordinal) and as a check-writing amount in dollars and cents.
Params: value: number
Example: https://units-convert.x402tookit.com/number-words?value=1234.56

### GET /roman-numerals — $0.02
Convert between integers (1-3999) and Roman numerals, and check whether a Roman numeral is written in canonical form.
Params: value: string
Example: https://units-convert.x402tookit.com/roman-numerals?value=1994

### GET /unit-convert — $0.02
Convert a value between units of length, mass, volume, area, speed, pressure, energy, power, time or temperature, exactly.
Params: value: number, from: string, to: string
Example: https://units-convert.x402tookit.com/unit-convert?value=26.2&from=mi&to=km

## Terms

Conversions are computed locally from the numbers you supply using standard definitions, provided as is. Cooking weights are typical averages that vary by brand and packing. Heat index and wind chill use the US National Weather Service formulas and are guidance, not safety advice.