How to Measure and Choose the Right Long Cardboard Box Size
Get the dimensions right first time with this long box sizing guide.
How to measure
Measurement steps0 / 5 checked
Quick answer
Measure the product, add 25-50mm per side for cushioning, and check the total against carrier limits. Always specify internal dimensions to your supplier. For long boxes, minimise width and height to reduce dimensional weight charges while leaving sufficient cushioning space. Check carrier surcharge thresholds (typically 120cm) before finalising length. Order samples and test-pack before committing to bulk.
Clearance and cushioning
Glass, electronics, and delicate items need generous cushioning space.
Metal parts, wood, and durable goods need minimal clearance.
The ends of long items are most vulnerable to impact damage.
Oversized boxes allow excessive movement, increasing damage risk.
Carrier size limits
Most UK parcel carriers surcharge above 120cm in any dimension and have hard limits around 150-200cm. Check your carrier limits before finalising box dimensions. If your product requires a box over 150cm, specialist or pallet carriers may be more cost-effective.
Carrier costs: shipping cost calculator or board grade guide.
Sizing tips
Long boxes in any size
Stock and custom long box sizes from ProcuraPack.
Browse long boxesFrequently asked questions
Measure the product at its longest, widest, and tallest, then add cushioning and wall thickness.
Always internal. Your supplier adds wall thickness to calculate external dimensions.
25-50mm per side for fragile items. 10-20mm for robust items.
120cm typically triggers surcharges. 150cm is a common hard limit. Check your specific carrier.
Yes, two-piece telescopic designs adjust to accommodate different product lengths.
Part of our guide
Product Guide: Long Cardboard Boxes
Expert guides on long cardboard boxes for shipping oversized, elongated, and awkward items safely.
Browse all guides →
