Calculate grammage, burst value, or burst strength from any two inputs with units in g/m², oz/yd², kPa, or psi, and show steps.

Burst Value Calculator

Enter any 2 values to calculate the missing variable


Related Calculators

Burst Value Formula

The burst value calculator uses grammage, burst value, and burst strength. Burst value is also commonly called burst index.

BV = BS / G
  • BV = burst value or burst index, usually in kPa·m²/g
  • BS = burst strength, usually in kPa
  • G = grammage, usually in g/m²

The same relationship can be rearranged depending on which value you need to calculate:

BS = G * BV
G = BS / BV
  • To calculate burst value: enter grammage and burst strength. The calculator divides burst strength by grammage.
  • To calculate burst strength: enter grammage and burst value. The calculator multiplies grammage by burst value.
  • To calculate grammage: enter burst strength and burst value. The calculator divides burst strength by burst value.

The calculator converts all inputs to base units before calculating: grammage to g/m², burst strength to kPa, and burst value to kPa·m²/g. It then converts the result back to the unit you selected.

Burst Value Unit Conversions

Use these conversions to check results when switching between metric and imperial units.

Measurement Conversion Used by the calculator
Grammage 1 oz/yd² = 33.9057 g/m² Converts sheet basis weight to metric grammage
Burst strength 1 psi = 6.89476 kPa Converts pressure to kPa
Burst value 1 psi/(oz/yd²) = 0.203359 kPa·m²/g Converts burst index to metric units

Common Burst Value Inputs

Input What it represents Typical unit
Grammage Mass of paper, board, or sheet material per unit area g/m² or oz/yd²
Burst strength Pressure required to rupture the sheet during a burst test kPa or psi
Burst value Burst strength normalized by grammage kPa·m²/g or psi/(oz/yd²)

Burst Value Examples

Example 1: Calculate burst value

You have a sheet with a grammage of 120 g/m² and a burst strength of 360 kPa.

BV = BS / G
BV = 360 / 120 = 3.0000 kPa*m2 / g

The burst value is 3.0000 kPa·m²/g.

Example 2: Calculate burst strength

You have a grammage of 150 g/m² and a burst value of 2.8 kPa·m²/g.

BS = G * BV
BS = 150 * 2.8 = 420 kPa

The burst strength is 420 kPa.

Burst Value FAQ

Is burst value the same as burst index?

Yes. In this calculator, burst value and burst index mean the same thing. Both describe burst strength divided by grammage. The common metric unit is kPa·m²/g.

Why does grammage affect burst value?

Grammage is the mass per unit area of the sheet. Burst value normalizes burst strength by grammage, so two sheets with different basis weights can be compared more fairly. A heavier sheet may have a higher burst strength simply because it contains more material, but burst value adjusts for that weight difference.

Why do I need to enter exactly two values?

The formula contains three related variables: grammage, burst value, and burst strength. If you enter any two, the third can be calculated. If you enter fewer than two, there is not enough information. If you enter all three, there is no missing value to solve for.