Loading page
About this tool
Convert an Olympic weightlifting total into a Sinclair total using the official IWF bodyweight coefficient formula.
The Sinclair coefficient converts an Olympic weightlifting total into the total the same athlete would theoretically produce at the heaviest world-record bodyweight, so every category can be ranked on one list. The IWF formula is 10^(A × (log₁₀(bodyweight ÷ b))²), applied only below the reference bodyweight b — at or above b the coefficient is exactly 1.00. This calculator carries the published A and b constants for the 2021–2024 and 2017–2020 Olympic cycles and multiplies them by your snatch plus clean & jerk.
Open Sinclair Coefficient Calculator on AltFTool — it loads instantly in your browser.
Enter the values you already know.
Fine-tune the options to match your scenario.
Read the result and use it in your planning or reporting.
Carries the published A and b values per Olympic cycle rather than a single fixed table.
Coefficients above the reference bodyweight return exactly 1.00, as the IWF defines.
Rescore historical results with the constants that applied at the time.
Take the base-10 logarithm of bodyweight divided by the reference bodyweight b, square it, multiply by the cycle constant A, then raise 10 to that power. For a 100 kg man in the 2021–2024 cycle (A = 0.722762521, b = 193.609 kg) the coefficient is about 1.147, so a 400 kg total becomes a Sinclair total near 459.
b is the bodyweight of the world-record holder in the heaviest category, and A is a fitted constant derived from world-record data across the categories. The IWF recalculates both at the start of each Olympic cycle, which is why a Sinclair total from one cycle is not directly comparable with another.
It is designed to be neutral: the coefficient falls smoothly towards 1.00 as bodyweight approaches b, so a superheavyweight gets no multiplier while a 55 kg lifter gets a large one. Critics point out that the fit still reflects the record data of the cycle it was built from, so small biases can appear between categories.
Yes — the Sinclair–Meltzer–Faber (often called Sinclair–Malone–Meltzer) age factors multiply the Sinclair total by an additional age coefficient for masters competition. This calculator applies only the standard bodyweight coefficient, so masters results need that separate age factor applied afterwards.
Add the Sinclair Coefficient Calculatorwidget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
<iframe src="https://www.altftool.com/embed/widget/sinclair-coefficient-calculator"
title="Sinclair Coefficient Calculator — free AltFTool widget"
width="100%" height="640" style="border:0;border-radius:12px;overflow:hidden"
loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
<p style="font-size:12px;margin:4px 0 0">Widget by <a href="https://www.altftool.com/tools/all/sinclair-coefficient-calculator?utm_source=embed&utm_medium=widget">AltFTool — free online tools</a></p>