# Horsepower (mechanical) to Metric horsepower (PS) (hp to PS)

> Convert horsepower (mechanical) to metric horsepower (PS): 1 hp = 1.01387 PS. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

- Page id: `hp-to-ps` · Quantity: Power (`power`, base unit W) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/hp-to-ps · This document: https://tttkmbb.com/conversion/hp-to-ps.md · JSON: https://tttkmbb.com/conversion/hp-to-ps.json (add `?value=` for a result)

## Formula

- `1 hp = 1.01387 PS`
- `metric horsepower (PS) = horsepower (mechanical) × 1.013869665`
- Reverse: `horsepower (mechanical) = metric horsepower (PS) × 0.9863200706`

The factor follows from the SI definitions of both units (NIST SP 811); values below are rounded to 6 significant figures, the API returns up to 12.

## Worked examples

- 5 hp = 5.06935 PS
- 12.5 hp = 12.6734 PS
- 100 hp = 101.387 PS

## Conversion table

| Horsepower (mechanical) (hp) | Metric horsepower (PS) (PS) |
| --- | --- |
| 1 | 1.01387 |
| 2 | 2.02774 |
| 3 | 3.04161 |
| 4 | 4.05548 |
| 5 | 5.06935 |
| 6 | 6.08322 |
| 7 | 7.09709 |
| 8 | 8.11096 |
| 9 | 9.12483 |
| 10 | 10.1387 |
| 15 | 15.208 |
| 20 | 20.2774 |
| 25 | 25.3467 |
| 30 | 30.4161 |
| 40 | 40.5548 |
| 50 | 50.6935 |
| 75 | 76.0402 |
| 100 | 101.387 |
| 200 | 202.774 |
| 250 | 253.467 |
| 500 | 506.935 |
| 1000 | 1013.87 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=hp&to_unit=hp_metric` → unified JSON envelope with `result.values.result`, `formula`, `factor`, `sources`, `freshness`
- MCP: server `https://tttkmbb.com/mcp`, tool `convert_units` with `{"value":5,"from_unit":"hp","to_unit":"hp_metric"}`
- All power units: https://tttkmbb.com/api/v1/units?quantity=power · full converter: [Power Converter](https://tttkmbb.com/conversion/power.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**How many metric horsepower (PS) are in one horsepower?**

1 hp = 1.01387 PS. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

**What is the formula to convert horsepower (mechanical) to metric horsepower (PS)?**

Multiply the value in horsepower (mechanical) by 1.013869665: metric horsepower (PS) = horsepower (mechanical) × 1.013869665. For example, 5 hp = 5.06935 PS.

**How do I convert metric horsepower (PS) back to horsepower (mechanical)?**

Multiply by the inverse factor 0.9863200706 (horsepower (mechanical) = metric horsepower (PS) × 0.9863200706), or use the metric horsepower (PS)-to-horsepower (mechanical) page.

## Related conversions

- [Metric horsepower (PS) to horsepower (mechanical)](https://tttkmbb.com/conversion/ps-to-hp.md) (reverse)
- [Horsepower (mechanical) to Kilowatts](https://tttkmbb.com/conversion/hp-to-kw.md)
- [Kilowatts to Horsepower (mechanical)](https://tttkmbb.com/conversion/kw-to-hp.md)
- [Kilowatts to Watts](https://tttkmbb.com/conversion/kw-to-watts.md)
- [Watts to Kilowatts](https://tttkmbb.com/conversion/watts-to-kw.md)
- [BTU per hour to Watts](https://tttkmbb.com/conversion/btu-per-hour-to-watts.md)
- [Watts to BTU per hour](https://tttkmbb.com/conversion/watts-to-btu-per-hour.md)
- [Metric horsepower (PS) to Kilowatts](https://tttkmbb.com/conversion/ps-to-kw.md)
- [Kilowatts to Metric horsepower (PS)](https://tttkmbb.com/conversion/kw-to-ps.md)

## Data Sources

- NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors — https://www.nist.gov/pml/special-publication-811 (standard, retrieved 2026-09-24)
- BIPM – The International System of Units (SI Brochure, 9th edition) — https://www.bipm.org/en/publications/si-brochure (standard, retrieved 2026-09-24)
- Wikipedia – Conversion of units — https://en.wikipedia.org/wiki/Conversion_of_units (reference, retrieved 2026-09-24)