Calculator
Example Data Table
| Load (kg) | Mean Velocity (m/s) | Notes |
|---|---|---|
| 40 | 1.05 | Warm-up speed |
| 60 | 0.82 | Moderate effort |
| 80 | 0.62 | Working set |
| 95 | 0.45 | Heavy but controlled |
| 105 | 0.34 | Near max strength |
Formula Used
The calculator models the load–velocity relationship as a straight line: v = a·load + b.
- v is mean concentric velocity (m/s).
- load is external load (kg or lb).
- a is the slope (usually negative).
- b is the velocity intercept at zero load.
Using least-squares regression, the slope and intercept are:
b = ( Σy − a·Σx ) / n
From the fitted line, two useful points are derived: V0 = b and L0 = −b/a. Estimated 1RM uses your lift’s MVT: 1RM = (MVT − b) / a.
How to Use This Calculator
- Select your lift and units.
- Enter 3–10 load and velocity pairs.
- Use consistent depth, tempo, and rest.
- Press Calculate Profile to view results.
- Download CSV or PDF for recordkeeping.
What the profile represents
A load–velocity profile links external load to mean concentric bar speed for one lift. As load increases, velocity typically declines in an almost linear pattern within the tested range. The fitted line in this tool is v = a·load + b, where a is the slope and b is velocity at zero load (V0). For practical monitoring, use the same device, bar path, and intent each session so changes reflect readiness, not measurement noise. Record date, device, and lift conditions always.
Recommended testing loads
For most athletes, 4–8 data points provide a stable line without excessive fatigue. A common spread is roughly 30–85% of current capacity, using 2–3 warm-up loads plus 2–4 heavier loads. Keep rest consistent (2–4 minutes for moderate loads, longer for heavy). If you only test light loads, the slope can look too shallow; if you only test heavy loads, fatigue can depress velocities and steepen the slope.
Quality checks and R²
R² summarizes how tightly your points follow the fitted line. Values above 0.90 often indicate clean, repeatable technique, while lower values suggest inconsistent depth, bouncing, or mixed intent. Look for obvious outliers: a single rep with a misread velocity can shift both slope and intercept. When in doubt, remove one suspicious point and retest the line. Also keep loads monotonic; repeated identical loads with different velocities can reduce stability.
Using MVT for estimated 1RM
This calculator supports a lift-specific minimum velocity threshold (MVT) to estimate 1RM from the fitted line: 1RM = (MVT − b) / a. Typical defaults are 0.30 m/s for the back squat, 0.17 for the bench press, 0.20 for the deadlift, and 0.13 for the overhead press. If your estimate is below your heaviest tested load, add a heavier point or verify that velocities were recorded as mean concentric, not peak.
Programming from velocity zones
Velocity targets can translate directly into working loads for specific intents. The included reference targets are 0.20 m/s (max strength), 0.50 (strength‑speed), 0.80 (speed‑strength), and 1.10 (power/ballistic). The tool back-solves each target to a predicted load via load = (v − b) / a. Treat these as starting points: adjust 2–5% based on daily readiness and sport demands.
FAQs
1) What velocity should I enter?
Use mean concentric velocity from your device. If you only have rep velocity, average the concentric phase and avoid peak values. Consistency matters more than brand.
2) How many data points are enough?
Aim for 4–8 points across light to heavy loads. Fewer than three points can overfit, while too many heavy points can add fatigue and noise.
3) Why is my R² low?
Low R² usually reflects inconsistent depth, altered technique, or mixed effort. Re-test with consistent intent, longer rest, and remove one obvious outlier if the velocity reading looks wrong.
4) What is MVT and why it matters?
MVT is the slowest successful rep velocity for a lift. Using an appropriate MVT helps estimate 1RM from your profile, but it varies by athlete and equipment.
5) Can I use kilograms and pounds together?
No. Keep the same unit for every entry and for exported reports. If you switch units, the regression slope changes and zone loads will be wrong.
6) Does the calculator replace coaching judgment?
It provides a structured estimate, not a diagnosis. Use it to guide loading decisions, then adjust based on bar path, fatigue, and sport priorities.