Length add

length-add · version 1.0.0 · Units & sizes · free, no key needed

Add integer length terms in mixed units and return the exact sum in a chosen unit.

Use when you need to: length add · add length measurements · sum length terms into a unit.

Supported

• length add
• add length measurements
• sum length terms into a unit

Not supported

• more than 32 terms
• nautical miles
• floating-point lengths
• mean of lengths

Behavior

• terms is an array of 1 to 32 objects, each with a canonical integer value and a length unit.
• Each term is converted to nanometers as a BigInt and those amounts are summed.
• The nanometer sum is converted to the to unit as a reduced canonical rational.
• Negative term values are allowed; input -0 is canonicalized to 0.
• Input integers and the reduced numerator and denominator may have at most 1000 digits excluding sign.

Input

• terms (array of object, required): min items 1; max items 32
• to (one of "nm", "um", "mm", "cm", "m", "km", "in", "ft", "yd", "mi", required)

Output

• numerator (string, required): pattern ^(0|-?[1-9][0-9]*)$
• denominator (string, required): pattern ^[1-9][0-9]*$

Limits

• max digits: 1000
• max terms: 32
• units: ["nm","um","mm","cm","m","km","in","ft","yd","mi"]

Example

Request input:

{
  "terms": [
    {
      "value": "1",
      "unit": "ft"
    },
    {
      "value": "6",
      "unit": "in"
    }
  ],
  "to": "in"
}

Response:

{
  "result": {
    "numerator": "18",
    "denominator": "1"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "length-add",
  "version": "1.0.0",
  "input": {
    "terms": [
      {
        "value": "1",
        "unit": "ft"
      },
      {
        "value": "6",
        "unit": "in"
      }
    ],
    "to": "in"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/length-add/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"terms":[{"value":"1","unit":"ft"},{"value":"6","unit":"in"}],"to":"in"}'

The machine-readable contract is at /v1/tools/length-add/versions/1.0.0.

CLI

node cli.mjs run length-add 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Byte size add: Add non-negative integer byte-size terms in mixed IEC units and return the exact sum in a chosen unit.
• Length compare: Compare two integer length measurements by exact nanometer amounts.
• Mass add: Add mixed-unit canonical integer mass amounts and express the sum in a target unit as a reduced rational.
• Length convert: Convert a canonical integer length between exact SI and international customary units.
• Byte size compare: Compare two non-negative integer byte sizes by exact byte amounts.
• Byte size convert: Convert a non-negative integer byte size between IEC binary units as an exact rational.