🏋️Weight Converter
Convert between weight and mass units: metric tons, kilograms, grams, milligrams, pounds, ounces and stones with exact international definitions.
Worked examples
1 Metric tons in Kilograms
GET /api/v1/converters/weight-converter?value=1&from=t&to=kg
Result: 1,000 kg
100 Metric tons in Kilograms
GET /api/v1/converters/weight-converter?value=100&from=t&to=kg
Result: 100,000 kg
5 Kilograms in Metric tons
GET /api/v1/converters/weight-converter?value=5&from=kg&to=t
Result: 0.005 t
2 Metric tons in Grams
GET /api/v1/converters/weight-converter?value=2&from=t&to=g
Result: 2,000,000 g
Machine API (x402)
$0.001 / callThis tool is also a JSON API for AI agents. Requests without payment receive 402 Payment Required plus instructions; agents pay USDC on Base via the x402 protocol — no accounts, no API keys.
GET /api/v1/converters/weight-converter?value=1&from=t&to=kg HTTP/1.1
Host: agenttools-hub.vercel.app
→ 402 (payment required, instructions in headers)
→ 200 (after X-PAYMENT header; JSON body below)
{
"tool": "converters/weight-converter",
"input": {"value":1,"from":"t","to":"kg"},
"result": { "value": 1000, "answer": "1,000 kg" }
}Agent docs: /llms.txt · OpenAPI spec · integration guide
About this tool
Convert weight and mass between the metric system and imperial units using the exact 1959 international yard-and-pound definitions — kilograms, pounds, ounces, stones and tons.
value × tfactor ÷ target factor (all units relate to the kg base)
Frequently asked questions
How many pounds in a kilogram?
One kilogram is exactly 2.20462262185 pounds; the pound is defined as exactly 0.45359237 kg.
How many grams in an ounce?
One avoirdupois ounce is exactly 28.349523125 grams. (A troy ounce, used for precious metals, is 31.1034768 g.)
What is a stone?
A stone is 14 pounds (6.35029318 kg), still commonly used for body weight in the UK and Ireland.