Product to Box Dimensions Calculator
Add allowances on both opposing faces. Internal fit dimensions and external shipping dimensions remain separate. Use final converter-confirmed external measurements before requesting freight.
Use a saved product specification (optional)
Enter your values
First time using this calculator?
Replace the example values with figures from your supplier sheet or measurements. Choose the unit beside each value. Results update as you type; fix any highlighted field before using the result.
GSM means grams per square metre. Net weight excludes the core and other packaging. MOQ means the minimum order quantity. An optional field can stay blank unless the result you need depends on it.
Prices keep the selected currency; changing its label does not convert an exchange rate. Save or export the result after checking your inputs.
Help with board thickness
Use the measured or specified material thickness. One micron (µm) is one thousandth of a millimetre.
Internal length
Internal side = Product side + 2 × (Clearance + Cushioning); External side = Internal side + 2 × Board
l = 200; w = 150; h = 100; clear = 5; cushion = 10; board = 4 → Internal length = 230 mm; Internal width = 180 mm; Internal height = 130 mm; External length = 238 mm; External width = 188 mm; External height = 138 mmSaved calculations stay in this browser. No account or cloud backup is created.
Save to a product project (optional)
Choose or create a saved product project ↗This is an illustrative example. Saved or transferred values must be checked against your job.
Calculated from your inputs. Confirm specifications with your supplier.
How sensitive is this result to your assumptions?
Vary one input and inspect internal length
All other entered inputs stay fixed. Ranges are your scenarios, not statistical confidence or supplier performance predictions. This uses the same validated calculator engine.
The formula, made clear.
Add allowances on both opposing faces. Internal fit dimensions and external shipping dimensions remain separate. Use final converter-confirmed external measurements before requesting freight.
How to use this calculator
- 01
Confirm product length, product width, product height, clearance per side, cushioning per side, board thickness.
- 02
Enter consistent units; zero means a confirmed absence of a charge or allowance.
- 03
Review the arithmetic, rounding and limitations before using the result in a purchasing decision.
A calculation you can check
A 200 mm product with 5 mm clearance and 10 mm cushioning per side needs 230 mm internal length; 4 mm board gives an estimated 238 mm external length.
- Product length
- 200 mm
- Product width
- 150 mm
- Product height
- 100 mm
- Clearance per side
- 5 mm
- Cushioning per side
- 10 mm
- Board thickness
- 4 mm
l = 200; w = 150; h = 100; clear = 5; cushion = 10; board = 4 → Internal length = 230 mm; Internal width = 180 mm; Internal height = 130 mm; External length = 238 mm; External width = 188 mm; External height = 138 mmCheck the displayed formula and units against your quotation. Use measured GSM, net weight and actual layout dimensions where available. Default densities are planning assumptions, not certified material properties. Calculated cost does not certify strength, compatibility or safe loading.
Method, units and material assumptions ↗