What size backpack do I need for a weekend trip?

For a 2-3 day trip with three-season gear, a 40-55L pack is typical. Ultralight hikers can manage with 30-40L. Winter trips need 55-70L due to bulkier insulation. Day hikes require only 20-30L.

Is it better to have a pack that is too big or too small?

Slightly too big is generally better than too small. An oversized pack can be cinched down with compression straps, but a too-small pack forces you to strap items externally, which affects balance and can snag on branches. However, a much-too-large pack encourages packing unnecessary items.

How do I measure backpack volume?

Manufacturers measure volume by filling the pack with small balls or beads and measuring the displacement. Volumes include the main compartment and permanent pockets. Mesh pockets, hip belt pockets and lid pockets may or may not be included in the stated volume — check the specifications.

CampCalcs

Backpack Volume Calculator

Determine the right backpack size in litres based on trip length and gear requirements.

Trip Length

Season

Shelter Type

Include cooking gear

How We Calculate This

This calculator estimates the pack volume needed by adding up the volume requirements of each gear category.

Total volume = Shelter + Sleep system + Clothing + Food + Cooking + Miscellaneous

A 15-20% buffer is included in the recommended range to allow for packing inefficiency and personal items.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.