# Geospatial Resolution & Scale Denominator Calculator

> Geospatial Resolution & Scale Denominator Calculator is a paid API for AI agents from geospatial.openverbs.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-16).

Returns the ground resolution in metres per pixel (for 256-px tiles) and the OGC map scale denominator for a given slippy-map zoom level, with optional latitude correction.

## Facts

- Endpoint: POST https://geospatial.openverbs.com/v1/resolution
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/geospatial-resolution-scale-denominator-calculator-f499a0f3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_i65A2qGNBao-Oy68mbunO

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability geospatial-resolution-scale-denominator-calculator-f499a0f3 -d '<json body>'
```

Example prompt: What's the ground resolution in metres per pixel and the OGC scale denominator for zoom level 14, corrected for latitude 51.5?

## When to prefer this

Choose this endpoint when you need precise ground resolution (metres per pixel) or OGC scale denominator values for slippy-map (XYZ/OSM/Google) tiles at a specific zoom level. Especially useful when latitude-corrected resolution is needed (e.g. for tiles far from the equator). Prefer this over manual calculation to avoid projection errors in Web Mercator.

## Known failure modes

- Missing required 'zoom' field returns a validation error
- Zoom level outside 0–30 range is rejected with a range error
- Latitude outside -90 to 90 degrees is rejected with a validation error
- Invalid body type or malformed JSON returns a parsing error
- Payment not included or insufficient triggers a 402 Payment Required response

## How this service works

Report the ground resolution (metres per pixel, for 256-px tiles) and the OGC map scale denominator at a zoom level, optionally adjusted for latitude (default equator).

## Output

Returns the ground resolution in metres per pixel for a 256-px slippy-map tile at the specified zoom level (optionally cosine-corrected for the given latitude), along with the OGC map scale denominator corresponding to that zoom level.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "zoom"
     ],
     "properties": {
      "lat": {
       "type": "number",
       "maximum": 90,
       "minimum": -90,
       "description": "Latitude for the cos(lat) correction. Default 0."
      },
      "zoom": {
       "type": "integer",
       "maximum": 30,
       "minimum": 0,
       "description": "Zoom level."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/geospatial-resolution-scale-denominator-calculator-f499a0f3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from geospatial.openverbs.com](https://www.zero.xyz/host/geospatial.openverbs.com/llms.txt)