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1RM Projection Engine

Predict your contest-day 1RM using statistical modeling of your training history

Current Strength

Training Profile

E1RM History (Optional)

Enter recent E1RM values to improve projection accuracy with linear regression. At least 3 data points recommended.

Predict Your Contest-Day Strength

Enter your current maxes, contest date, and training profile. Optionally add E1RM history data points for regression-based predictions with confidence intervals.

Projected Contest-Day 1RM

Projected Total (Expected)

Optimistic: Conservative:

Projection Method

Confidence interval widens as the contest date is further away. Bodyweight trend, training frequency, and average RPE are factored into all scenarios.

Projected Strength Trajectory

Dotted lines show the expected, optimistic, and conservative trajectories to contest day. Historical data points (if entered) are shown as filled circles.

What-If Scenarios

How much does training frequency and RPE range affect your projected total?

Scenario Squat Bench Deadlift Total vs Current Plan

Regression Analysis

Linear regression on your entered E1RM data points. The slope shows your weekly strength gain rate.

Related Calculators

Periodization Optimizer Build your full contest prep plan Peaking Calculator Week-by-week competition taper E1RM Calculator Estimate your current 1RM from sets

How 1RM Projections Are Calculated

The 1RM Projection Engine uses a simplified Bayesian approach combining linear regression on your training history with sport-science-based growth rate modeling.

When historical E1RM data points are provided, the engine performs ordinary least-squares regression on each lift independently, extrapolating the trend line to the contest date. The confidence interval widens with the square root of the projection horizon, reflecting increased uncertainty further into the future.

Without historical data, the engine uses experience-based growth curves: beginners can gain 1-2% of 1RM per week, intermediates 0.3-0.8%, and advanced athletes 0.1-0.3%. Training frequency applies a multiplier (more sessions = slightly faster adaptation), average RPE adjusts for stimulus quality, and bodyweight trends apply allometric scaling.

The three scenarios - optimistic, expected, conservative - represent the 85th, 50th, and 15th percentile outcomes based on variability typical for each experience level.

Frequently Asked Questions

At 4-8 weeks out, expected projections are typically within 3-5% of actual contest performance for intermediate lifters following structured programming. Accuracy drops for longer horizons (12+ weeks) and for beginners whose rate of adaptation is harder to predict. The conservative scenario is your planning baseline - if you hit the expected, that is a good outcome.
The optimistic and conservative values represent the range within which ~70% of similar athletes would land. Think of it as one standard deviation above and below the expected value. The gap widens with time because more things can change (injury, life stress, programming adjustments) over a longer horizon.
Bodyweight and strength are related via allometric scaling. Gaining mass typically increases absolute strength, while cutting mass can temporarily reduce strength even if relative strength improves. Aggressive cuts reduce all three projected lifts by 2-5%, while a gaining phase increases projections by 1-3%. These are averages - individual responses vary significantly.
R² measures how well the linear trend fits your entered data points. R² above 0.85 means the trend is strong and projections are more reliable. R² below 0.5 means high variability in your training data, which widens the confidence interval. More data points over a longer window improve the regression fit.
Use the conservative projection for planning your opener and second attempt. Reserve the optimistic projection for your third attempt goal if everything goes perfectly. Competing for the conservative total ensures you go 9-for-9 even on a bad day, while leaving room to hit lifetime PRs if the contest goes well.

1RM projections are statistical estimates based on general strength development models. Individual results vary based on training quality, recovery, nutrition, and many other factors. These projections are not guarantees. Always consult your coach when planning competition attempts.