Shore Hardness Conversion Calculator
In this shore hardness conversion calculator, choose your current Shore scale (A, D, 00, M, E, or C), Select the desired conversion scale. Input the hardness reading (0-100) and adjust test temperature (optional, defaults to 23°C).
The calculator will compute the approximate converted value.
If you have a Shore A reading of 90, the calculator would process this hardness value to determine equivalent values in other scales, such as approximately 40 Shore D or 95 Shore 00.
Shore Hardness Conversion Table
| Shore 00 | Shore A | Shore D | Material Examples |
|---|---|---|---|
| 10 | – | – | Soft gel-like materials (e.g., soft gels). |
| 20 | 0 | – | Very soft rubber or foam. |
| 30 | 5 | – | Soft polyurethane. |
| 40 | 10 | – | Soft silicone rubber. |
| 50 | 15 | – | Flexible elastomers. |
| 60 | 20 | – | Medium rubber. |
| 70 | 25 | – | Semi-soft plastics. |
| 80 | 35 | – | Stiff rubber or semi-rigid plastics. |
| 90 | 40 | – | Hard rubber. |
| 95 | 50 | – | Semi-rigid materials. |
| – | 60 | 5 | Soft rigid plastics. |
| – | 70 | 15 | Medium rigid plastics. |
| – | 80 | 30 | Rigid plastics. |
| – | 90 | 50 | Very rigid materials (e.g., hard plastics). |
| – | 100 | 70 | Extremely hard materials (e.g., polycarbonate) |
Shore Hardness Conversion Formula
From Shore A to Shore D: D = 0.0235 * A^2 + 0.4 * A - 1.6From Shore D to Shore A: A = -1.0465 * D^2 + 12.33 * D - 53.67Basic Scale Conversion Formula:
Converted Value = (Original Value × Source Factor) ÷ Target FactorTemperature Compensation Formula:
Adjusted Value = Original Value × (1 - (TempCoeff × (T-23)/100))Scale Factor Formula:
Shore A = 1.0
Shore D = 2.66
Shore 00 = 0.5
Shore M = 0.75
Shore E = 1.33
Shore C = 2.5For a 90 Shore A measurement, conversions would be:
Shore D = 90 × (1/2.66) = ~34
Shore 00 = 90 × (1/0.5) = ~95 (max 100)What are Shore Hardness Typical Values?
For common materials, typical ranges include:
- Soft Rubber: Shore A: 40-60, Shore D: 15-25
- Medium Rubber: Shore A: 60-80, Shore D: 25-35
- Hard Rubber: Shore A: 80-95, Shore D: 35-45
- Soft Plastics: Shore D: 30-50, Shore A: 95-100
- Hard Plastics: Shore D: 60-85, Shore A: N/A
How to Calculate Shore Hardness?
- Force Application: Apply a specific force (usually 822 grams for Shore A)
- Depth Measurement: Measure indentation depth (ranging 0-2.5mm)
- Scale Conversion: Convert the depth to a hardness value (0-100)
Example calculation:
- Indentation depth: 0.5mm
- Maximum depth: 2.5mm
- Shore A = 100 × (1 – (0.5/2.5)) = 80
- Soft Rubber Band: Measured: 40 Shore A, Shore D conversion: (40 – 40) × 0.5 = 0 Shore D
- Car Tire: Measured: 70 Shore A, Shore D conversion: (70 – 40) × 0.5 = 15 Shore D
- Hard Rubber Sole: Measured: 95 Shore A, Shore D conversion: (95 – 40) × 0.5 = 27.5 Shore D
- Medium Hardness O-Ring: Measured: 60 Shore A, Shore C conversion: (60 × 1.02) – 25 = 36.2 Shore C
- Industrial Gasket: Measured: 75 Shore A, Shore C conversion: (75 × 1.02) – 25 = 51.5 Shore C
Shore A to Shore D Hardness Conversion
The Shore D scale is used for harder materials than Shore A. Here’s a quick reference:
- Shore A 80 ≈ Shore D 29
- Shore A 90 ≈ Shore D 39
- Shore A 95 ≈ Shore D 46
Shore A to Shore C Conversion
Shore C sits between A and D scales and is less commonly used. A rough conversion guideline: Shore C ≈ (Shore A × 1.02) – 25
What is Shore Hardness?
Shore hardness is a standardized measurement that indicates a material’s resistance to indentation. It’s like a material’s firmness signature – uniquely describing its surface hardness and compressive resistance.