About this tool
Backpack Weight Calculator is a free, in-browser tool that rates how heavy your pack is relative to your body weight — the metric hikers and backpackers use to avoid injury and fatigue. Enter your body weight and the loaded pack weight (in pounds or kilograms), choose a day hike or a multi-day trip, and it shows your pack as a percentage of body weight with a clear pass or fail. All calculations run on your device; nothing is uploaded.
The widely used guideline is that a loaded pack should not exceed about 20% of your body weight for a day hike, or roughly 25% for a longer, multi-day trip. The tool divides pack weight by body weight and multiplies by 100 to get the percentage, then compares it to the target and flags anything over. It also shows the recommended maximum weight for your target and a 10% base-weight goal — the weight of your gear before food, water and fuel — which experienced backpackers keep low.
Use it while packing: if the percentage is over the limit, look for the heaviest non-essential items to leave behind or swap for lighter gear. Lighter loads mean fewer blisters, less knee and back strain, and more enjoyable miles — especially for beginners, children and anyone carrying a full multi-day kit.