What this calculator solves

Use Void Fill to estimate the unoccupied rectangular volume after a stated quantity of products is placed in a carton. The fill factor converts that geometric void into an adjustable operational demand. It differs from Packing Paper, which turns void into sheets using a tested sheet yield.

How to choose the inputs

Use internal box dimensions and protected product dimensions in the same unit. Enter the quantity actually sharing the carton and choose a fill factor from a documented packing trial: above 1.0 can cover compression or inaccessible pockets, while below 1.0 should only reflect a validated method.

InputHow to prepare it
Box internal lengthMeasure box internal length on the finished item or container surface named here; keep it in the selected unit and include normal production variation.
Box internal widthMeasure box internal width on the finished item or container surface named here; keep it in the selected unit and include normal production variation.
Box internal heightMeasure box internal height on the finished item or container surface named here; keep it in the selected unit and include normal production variation.
Product lengthMeasure product length on the finished item or container surface named here; keep it in the selected unit and include normal production variation.
Product widthMeasure product width on the finished item or container surface named here; keep it in the selected unit and include normal production variation.
Product heightMeasure product height on the finished item or container surface named here; keep it in the selected unit and include normal production variation.
Product quantityCount product quantity in the exact operating unit shown on the dispatch or inventory record; do not mix eaches, packs, cases, or layers.
Fill factorSet fill factor from a documented trial or approved method and retain the value with the calculation record.

How the calculation works

Estimated fill = (box volume − total product volume) × fill factor
  1. Validate the Void Fill Calculator manifest: confirm that box internal length, box internal width, box internal height describe the same Void Fill Calculator pack, batch, or planning period.
  2. Calculate empty volume: apply Estimated fill = (box volume − total product volume) × fill factor without rounding intermediate values for Void Fill Calculator.
  3. Review the empty volume breakdown: use the primary result for the stated decision and the secondary values to identify the input or constraint driving this Void Fill Calculator result.

Worked example

A 14 × 10 × 8 in box around one 10 × 6 × 4 in product leaves 880 in³. At a 1.0 fill factor, estimate 880 in³ of loose filled volume.

Next action: After: calibrate the result with Packing Paper or a supplier-specific dispensing trial.

How to interpret the result

A high empty share suggests checking a smaller carton, a different orientation, or structural inserts before ordering more loose fill. A low share does not guarantee protection; heavy or fragile items may need blocking, bracing, or suspension. Convert the volume through the material’s measured yield.

Common mistakes

  • Using external box dimensions.
  • Multiplying product quantity but not checking whether the arrangement is physically possible.
  • Treating loose-fill volume as structural cushioning performance.
  • Keeping an old fill factor after changing paper, equipment, or operator method.

Assumptions and limitations

Products are simplified to rectangular blocks and all leftover volume is treated as accessible. The model excludes nesting, irregular pockets, compression recovery, product movement, impact performance, and material density.

Void Fill Calculator estimate only: verify the Void Fill Calculator empty volume with the physical pack or operating record and the current requirements governing this decision.

Related workflow

  1. Before: confirm product fit and the protection function.
  2. After: calibrate the result with Packing Paper or a supplier-specific dispensing trial.

Last reviewed: July 26, 2026