Ruck Weight Calculator
Find safe ruck pack weight from body weight and fitness level.
What it does
Rucking is walking with a loaded pack. Load turns an easy walk into strength and engine work, but too much too soon punishes feet, knees, and backs.
The tool above sets pack weight from body weight. A 180 lb walker at the standard 20 % carries 36 lb, after starting near 18 lb for the first 2 weeks. Metric walkers get the same plan as 82 kg toward 16.4 kg.
Shares keep loads fair across sizes. Light 10 % suits new walkers and return from layoff, standard 20 % suits fit walkers on rolling ground, and near 33 % suits advanced walkers with pack fit and coaching.
Progression matters more than any single number. Feet adapt to miles before they adapt to pounds, so build distance first, then load, and never jump both in one week.
Pack fit can make or break the plan. A 36 lb load riding high and tight walks lighter than the same plates slung low, and shoes with room for warm feet prevent most blisters.
How to use
- Pick imperial (lb) or metric (kg).
- Enter body weight.
- Pick level: light 10, standard 20, advanced 33.
- Read target pack weight first.
- Read the share line to check the band.
- Start at the 10 % line for 2 weeks, then build.
Formula
- body
- Morning body weight.
- level
- 10, 20, or 33 by fitness.
Level shares are 10 % light, 20 % standard, and 33 % advanced. The starter line always shows 10 % for the first 2 weeks, whatever the target.
Worked example
Example: 180 lb at 20 %
Imperial defaults: 180 lb body weight at standard 20 %. These are also the default values, so the page opens on this answer.
- Body weight: 180 lb.
- Level: standard, or 20 % of body weight.
- Target: 180 x 0.20 = 36 lb.
- Starter: 180 x 0.10 = 18 lb for the first 2 weeks.
- Share: 20 % of body weight.
- Tool shows 36 lb, 20 % of body weight, Start with 18 lb for 2 weeks.
Reference table
| Body | Light 10 % | Standard 20 % |
|---|---|---|
| 150 lb | 15 lb | 30 lb |
| 180 lb | 18 lb | 36 lb |
| 200 lb | 20 lb | 40 lb |
| 82 kg | 8.2 kg | 16.4 kg |
Limits
- Training guide only, not duty doctrine or medical advice.
- Ignores grade, heat, and pack fit, which shift strain.
- Joint pain and heart signs need a clinician, not more miles.
- Advanced shares need coaching and slow buildup.
Common mistakes
- Starting at 33 % with no base miles.
- Adding load, pace, and distance in the same week.
- Wearing new boots on a long loaded walk.
- Letting the pack ride low and loose.
- Skipping foot checks until blisters burst.
Try it yourself
Quick checks. Answers sit tucked under each question.
150 lb at 20 %?
150 x 0.20 = 30 lb. Starter is 150 x 0.10 = 15 lb for 2 weeks.
70 kg at light 10 %?
70 x 0.10 = 7 kg. This is also the starter and the target at light level.
Questions
How heavy should my ruck be?
Multiply body weight by the level share. A 180 lb walker at 20 % carries 36 lb.
Where should a new walker start?
Start near 10 % for 2 weeks, then build toward 20 %. Advanced troops may reach near 33 % with coaching and pack fit.
What matters besides weight?
Pack fit, shoes, route grade, and pace. A 36 lb load on flat paths differs sharply from the same load on hills.
What pain means stop?
Stop and check feet, knees, and back. Blisters, joint pain, and altered stride mean cut load or distance first.
Can new walkers progress weekly?
Yes, when load, pace, and distance rise slowly. Add only one of the three each week.
Is this Army doctrine?
No. This page plans training load only. Duty loads follow unit rules and leader guidance.