OFFICIAL STREETLIFTING
1RM Predictor Suite
Advanced mode includes sensitivity, calibration, and training-to-competition tools where relevant.
STEP 1 — Master Bodyweight (applies to Muscle-Up / Pull / Dip)
kg
lb

Muscle-Up 1RM Predictor

Units
kg
lb
DataResult
STEP 2 — Select Form Standard
Also estimate OSL Competition Form from this Training Form set.
Conversion factor: 92%
Fine-tune if needed. If you move the slider, preset switches to Custom.
STEP 2 — Enter Lift Data
STEP 4 — Personal Adjustment (Optional)
You don't need to touch this. Only adjust if you want more conservative or more generous predictions.
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STEP 5 — Calibration (Optional)
Enter a known true 1RM to personalize future predictions to your strength profile.
Enable calibration
Estimated 1RM (added weight)
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Estimated OSL Competition Form (from training set)
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Estimated Combined Total
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Total = sum of all current 1RM predictions

FAQ’s

    1. (MU / Pull / Dip only) STEP 1: Enter your Master Bodyweight once at the top.

    2. Go to the lift tab you want (Muscle-Up / Pull / Dip / Squat).

    3. Enter weight used, reps, and RIR.

    4. Press Predict.

    5. Your estimated 1RM displays below. The Live Total updates automatically.

  • Advanced mode — including Personal Adjustment and Calibration — is available for all four lifts, including Squat.

    1 - (MU / Pull / Dip only) STEP 1: Enter your Master Bodyweight once at the top.

    2 - Switch to Advanced.

    3 - (Muscle-Up & Pull only) Choose your form standard:

    • OSL Competition Form — strict judging standard

    • Training Form (Kipping) — allows realistic training compensation

    4 - Enter weight used, reps, and RIR.

    5 - Training Quality Preset (MU / Pull only) - For Training Form only
    If you selected Training Form, choose how clean your reps were:

    • Messy

    • Standard

    • Clean-ish

    • Custom: fine-tune using the slider if needed.

    6 - Personal Adjustment (Optional)
    Adjust how much you trust the calculator's average prediction. 100% means take the average as-is; move it up or down for more or less generous estimates. (You usually don't need to touch this.)

    7 - Calibration (Optional)
    Enter a known real 1RM and press Calibrate to personalise predictions to your strength profile.

    8 - Press Predict to generate your estimate.

    9 - If using Training Form, you can also view an estimated Competition Form 1RM based on your rep quality.

    10 - Your predicted max appears below, and the Live Total updates automatically.

  • Calibration Explained

    Purpose:
    Calibration adjusts the calculator so predictions match your real strength level.

    When to use calibration
    Use it if:

    • you know your real 1RM

    • predictions seem slightly off for you

    • you want more personalised estimates

    You don't have to use it. The calculator works fine without it.

    How to calibrate

    Calibration needs two things: a recent set you performed, and a 1RM you already know (from a previous test or competition) — not a fresh max attempt.

    1. Enter your lift data (weight, reps, RIR — plus bodyweight, for Muscle-Up, Pull, and Dip) from a recent heavy set.

    2. Turn on Enable Calibration.

    3. Enter your already-known true 1RM.

    4. Click Calibrate.

    The calculator compares what it would have predicted from your set against your real number, and uses the gap to adjust all future predictions automatically.

    Choosing the right set for calibration

    For best accuracy, use a set that was:

    • recent

    • 3–6 reps (not a 1-rep attempt — at 1 rep the formulas already predict close to the actual weight, so there's little gap left to learn from)

    • 0–1 RIR

    • done with comp form

    Avoid using:

    • very old maxes

    • fatigued sessions

    After calibration

    • Predictions update instantly

    • No need to recalibrate each session

    • Only recalibrate if your strength significantly changes

    Resetting calibration
    Press Reset to return the calculator to default prediction settings.