Ruck Pace Calculator
Put in a distance and either a pace or a finish time. You get the other one, the per-mile splits to carry in your head, and an honest read on where that pace sits against the standards people are actually graded on.
e.g. 14:30
e.g. 2:45 or 2:45:00
Add load and body weight for an energy estimate
Ruck, water, weapon, kit
Estimated with the Pandolf load-carriage equation — the standard model for the metabolic cost of marching under load, and the one the Lensatic app uses to score a ruck. It assumes walking on a firm surface; treat it as a planning figure, not a measurement.
Your splits
Even splits, mile by mile. A ruck is won by knowing what the watch should say at mile 4, not by finding out at mile 11 that it was never going to happen.
| Mile | Elapsed | Remaining |
|---|
Where that pace sits
Your current pace against the 12-mile marks that get quoted most often — the Army foot march, the SFRE, and the minimum and goal published in the SFAS Preparation Handbook. Go by the standard in your own orders.
| Mark | 12-mile time | Pace | You |
|---|
How to actually use this
Train at the pace, not near it
A 15:00 mile and a 13:30 mile are different activities. One is a fast walk; the other is at or past the point where most people's walking gait breaks down and they start shuffling. If your goal pace is 13:30 and every training ruck sits at 15:30 because that is what feels sustainable, you have trained a pace you do not intend to march.
The usual fix is to stop treating every ruck the same. One long ruck a week at an easy pace to build tissue tolerance, one shorter ruck at or slightly faster than goal pace to teach the gait. Four miles at 12:45 does more for a 12-mile goal than eight miles at 16:00.
Negative splits are a fantasy under load
Almost nobody rucks a 12-miler faster in the back half than the front. Feet, shoulders and hips accumulate damage, and the pace bleeds off whether you agree to it or not. Plan the even splits above, expect to lose 15–30 seconds a mile in the last third, and build the cushion at the start rather than hoping to find it at the end.
The weight on the scale is not the weight on your back
A "45-pound" ruck is 45 pounds dry. Add three liters of water (about 6.6 lb), the bag, the weapon, and whatever else is on the packing list and the real number is often 65 to 75. Train with the number you will carry, weighed on a scale, not the number written on the sheet.
Of everything measured at selection, road march performance is consistently the strongest single predictor of whether a candidate finishes. It is also the most trainable — it responds to patient, boring volume more reliably than almost anything else on the list. If you have limited hours a week, this is where they go.
Rucks that grade themselves
Lensatic tracks the ruck by GPS with the screen off, splits it by mile with pace bars and heart-rate zones, and scores the calorie cost with the same Pandolf equation used above. Road to 12 Miles builds the distance from wherever you are now; the 12-week SFAS Prep plan runs the whole block. Your ruck PRs populate the standards board automatically.
See the training plans All guidesCommon questions
What is a good 12-mile ruck time?
Three hours — a 15:00 mile — is the number most commonly used as a pass on an Army foot march and at Ranger School's RAP week. Candidates preparing for SFAS generally aim well under that; 12:00 to 13:00 per mile is the range usually described as competitive. Under 2:30 for twelve miles with a real load is a strong result for anyone.
How much weight should I train with?
Most preparation is done between 35 and 55 pounds dry. Going heavier than the standard you are training for is a common mistake — it buys very little adaptation and costs a great deal in feet, knees and back. Build the distance first at a moderate load, then the pace, then add weight last.
Should I run with a ruck?
Rarely, and never as the main dish. Ruck running loads the joints far harder than marching and is responsible for a large share of preparation injuries. Most fast rucking is a very fast walk, not a jog, and the people who march 12:30 miles are usually walking every step of it.
Does the calculator account for hills?
The pace and split figures are flat-ground arithmetic — distance divided by time. The optional energy estimate does take an average grade, because the metabolic cost of climbing under load is where most of the extra work goes. For a hilly route, plan your splits by terrain rather than by even miles.
Is this an official Army calculator?
No. Lensatic is a product of Deadlift Digital LLC and has no affiliation with the U.S. Army or the Department of Defense. The standards listed are the ones widely published and discussed by candidates; the authority for any standard you will be held to is the order or packing list you were given.