# Pounds per cubic inch to Grams per cubic centimeter (lb/in³ to g/cm³)

> Convert pounds per cubic inch to grams per cubic centimeter: 1 lb/in³ = 27.6799 g/cm³. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

- Page id: `lb-per-in3-to-g-per-cm3` · Quantity: Density (`density`, base unit kg/m3) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/lb-per-in3-to-g-per-cm3 · This document: https://tttkmbb.com/conversion/lb-per-in3-to-g-per-cm3.md · JSON: https://tttkmbb.com/conversion/lb-per-in3-to-g-per-cm3.json (add `?value=` for a result)

## Formula

- `1 lb/in³ = 27.6799 g/cm³`
- `grams per cubic centimeter = pounds per cubic inch × 27.67990471`
- Reverse: `pounds per cubic inch = grams per cubic centimeter × 0.036127292`

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 lb/in³ = 138.4 g/cm³
- 12.5 lb/in³ = 345.999 g/cm³
- 100 lb/in³ = 2767.99 g/cm³

## Conversion table

| Pounds per cubic inch (lb/in³) | Grams per cubic centimeter (g/cm³) |
| --- | --- |
| 1 | 27.6799 |
| 2 | 55.3598 |
| 3 | 83.0397 |
| 4 | 110.72 |
| 5 | 138.4 |
| 6 | 166.079 |
| 7 | 193.759 |
| 8 | 221.439 |
| 9 | 249.119 |
| 10 | 276.799 |
| 15 | 415.199 |
| 20 | 553.598 |
| 25 | 691.998 |
| 30 | 830.397 |
| 40 | 1107.2 |
| 50 | 1384 |
| 75 | 2075.99 |
| 100 | 2767.99 |
| 200 | 5535.98 |
| 250 | 6919.98 |
| 500 | 13840 |
| 1000 | 27679.9 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=lb%2Fin3&to_unit=g%2Fcm3` → 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":"lb/in3","to_unit":"g/cm3"}`
- All density units: https://tttkmbb.com/api/v1/units?quantity=density · full converter: [Density Converter](https://tttkmbb.com/conversion/density.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**How many grams per cubic centimeter are in one pound per cubic inch?**

1 lb/in³ = 27.6799 g/cm³. 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 pounds per cubic inch to grams per cubic centimeter?**

Multiply the value in pounds per cubic inch by 27.67990471: grams per cubic centimeter = pounds per cubic inch × 27.67990471. For example, 5 lb/in³ = 138.4 g/cm³.

**How do I convert grams per cubic centimeter back to pounds per cubic inch?**

Multiply by the inverse factor 0.036127292 (pounds per cubic inch = grams per cubic centimeter × 0.036127292), or use the grams per cubic centimeter-to-pounds per cubic inch page.

## Related conversions

- [Grams per cubic centimeter to pounds per cubic inch](https://tttkmbb.com/conversion/g-per-cm3-to-lb-per-in3.md) (reverse)
- [Kilograms per cubic meter to Grams per cubic centimeter](https://tttkmbb.com/conversion/kg-per-m3-to-g-per-cm3.md)
- [Grams per cubic centimeter to Kilograms per cubic meter](https://tttkmbb.com/conversion/g-per-cm3-to-kg-per-m3.md)
- [Kilograms per cubic meter to Pounds per cubic foot](https://tttkmbb.com/conversion/kg-per-m3-to-lb-per-ft3.md)
- [Pounds per cubic foot to Kilograms per cubic meter](https://tttkmbb.com/conversion/lb-per-ft3-to-kg-per-m3.md)
- [Grams per milliliter to Kilograms per cubic meter](https://tttkmbb.com/conversion/g-per-ml-to-kg-per-m3.md)
- [Kilograms per cubic meter to Grams per milliliter](https://tttkmbb.com/conversion/kg-per-m3-to-g-per-ml.md)
- [Pounds per US gallon to Kilograms per liter](https://tttkmbb.com/conversion/lb-per-gallon-to-kg-per-liter.md)
- [Kilograms per liter to Pounds per US gallon](https://tttkmbb.com/conversion/kg-per-liter-to-lb-per-gallon.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)