Kilonewtons to Poundals: 1 kN equals 7233.0115 pdl. To convert kilonewtons to poundals, multiply by 7233.0115 (pdl = kN × 7,233.01). For example, 10 kN = 72330.115 pdl.
How to Convert Kilonewtons to Poundals
To convert from kilonewtons to poundals, multiply the value by 7233.0115. The conversion is linear, meaning doubling the input doubles the output.
Conversion Formula
- Kilonewtons to Poundals:
pdl = kN × 7,233.01 - Poundals to Kilonewtons:
kN = pdl ÷ 7,233.01
Kilonewtons to Poundals Conversion Chart
| Kilonewtons (kN) | Poundals (pdl) |
|---|---|
| 0.1 | 723.30115 |
| 0.25 | 1808.252875 |
| 0.5 | 3616.50575 |
| 1 | 7233.0115 |
| 2 | 14466.023 |
| 3 | 21699.0345 |
| 5 | 36165.0575 |
| 10 | 72330.115 |
| 20 | 144660.23 |
| 25 | 180825.2875 |
| 50 | 361650.575 |
| 100 | 723301.15 |
| 250 | 1808252.875 |
| 1000 | 7233011.5 |
Understanding the Units
What is a Kilonewton?
A kilonewton equals 1,000 newtons.
Common contexts: structural engineering, climbing equipment ratings.
What is a Poundal?
A poundal equals approximately 0.138255 newtons — the force needed to accelerate one pound-mass by one foot per second squared.
Common contexts: absolute foot-pound-second system.
How to Convert Kilonewtons to Poundals
To convert kilonewtons to poundals, multiply by 7,233.01. A poundal is the foot–pound–second (FPS) absolute unit of force, defined as the force that accelerates one pound-mass at one foot per second squared. Numerically, 1 pdl ≈ 0.1382550 N; inverting and scaling by 1,000 gives the kilonewton conversion factor.
Conversion Formula
- Kilonewtons to poundals: pdl = kN × 7,233.01
- Poundals to kilonewtons: kN = pdl ÷ 7,233.01
- Scientific notation: 1 kN ≈ 7.23301 × 10³ pdl
The factor is exact within the precision of the defined pound (0.45359237 kg) and foot (0.3048 m). A handy comparison: 1 lbf ≈ 32.174 pdl — the dimensionless conversion is exactly standard gravity expressed in ft/s².
Common Conversions
| Kilonewtons (kN) | Poundals (pdl) | Approx. equivalent |
|---|---|---|
| 0.001 | 7.23 | ~7 pdl |
| 0.005 | 36.17 | ~36 pdl |
| 0.01 | 72.33 | ~72 pdl |
| 0.05 | 361.65 | ~362 pdl |
| 0.1 | 723.30 | ~723 pdl (~22.5 lbf) |
| 0.25 | 1,808.25 | ~1,808 pdl |
| 0.5 | 3,616.51 | ~3,617 pdl |
| 1 | 7,233.01 | ~7,233 pdl (~225 lbf) |
| 2.5 | 18,082.53 | ~18,083 pdl |
| 5 | 36,165.06 | ~36,165 pdl |
| 11.3 | 81,733.03 | ~81,733 pdl |
| 25 | 180,825.29 | ~180,825 pdl |
| 50 | 361,650.58 | ~361,651 pdl |
| 100 | 723,301.15 | ~723,301 pdl |
Understanding the Units
What Is a Kilonewton?
The kilonewton (kN) is 1,000 newtons — the SI engineering force unit. It is used wherever forces reach the structural-mechanical range: climbing carabiners (20–25 kN), suspension-bridge cable hangers (500–2,000 kN), vehicle drawbar pull, hydraulic-cylinder ratings, and post-tensioning tendons.
What Is a Poundal?
The poundal (symbol: pdl) is the absolute unit of force in the foot–pound–second (FPS) system: 1 pdl = 1 lb·ft/s². Numerically that comes to 0.138254954376 N. It is "absolute" in the same sense as the newton — defined directly from F = ma without reference to gravity — and so contrasts with the gravitational pound-force (lbf), which embeds standard gravity in its definition.
Three Imperial-style Force Systems
- FPS absolute (poundal): mass in lb, length in ft, force in pdl. F = m·a directly.
- FPS gravitational (slug, lbf): mass in slugs (1 slug ≈ 14.594 kg), force in lbf. F = m·a with no conversion constant.
- English engineering (lb, lbf): mass in lb, force in lbf. F = m·a requires the constant gc = 32.174 lb·ft/(lbf·s²) — a notorious source of confusion in older textbooks.
The Poundal in Physics and Engineering
The poundal was introduced in the late 19th century as part of an effort to give the FPS system the same conceptual cleanliness as CGS (where the dyne plays the analogous role) and, later, SI. By keeping the pound as a mass unit and defining force directly from F = ma, the poundal eliminated the need for the awkward constant gc. The trade-off: a poundal is small (~0.138 N), so most everyday engineering forces produced unwieldy numbers in poundals — a 200 lb person weighs about 6,400 pdl on Earth.
Pound-force won out for practical engineering because it directly mirrored what scales measured. The poundal survives mainly in older British physics textbooks (Tipler, Newman) and in some legacy aerodynamics and ballistics literature where momentum changes in slugs·ft/s versus impulse in pdl·s can simplify rocket and projectile equations. SI has replaced both in modern technical writing.
Related Force Converters
- Kilonewtons to Newtons — the standard SI step
- Poundals to Newtons — the pdl-to-SI bridge
- Newtons to Poundals — the reverse direction
- Kilonewtons to Pounds-force — gravitational FPS unit
- Pounds-force to Newtons — main US/UK-to-SI conversion
Brief History of the Poundal
The poundal was proposed by James Thomson in the 1870s and championed by his brother William Thomson (Lord Kelvin), who also helped formalise the CGS system in 1873. The aim was symmetry: give the British FPS system an absolute force unit analogous to the dyne. The 1873 Report of the BAAS Committee on dynamical and electrical units gave the poundal its first formal definition. It enjoyed a century of textbook life — particularly in mid-20th-century British physics — before being decisively overtaken by SI and, in US engineering practice, by the slug-based gravitational FPS system. Today it is a unit of historical and pedagogical interest more than active practice.