Sinclair Coefficient – Formula and What It Means

For a sport that seems like it should be super simple, weightlifting sure has made itself pretty complicated. In theory, weightlifting is nothing more than lifting as much weight as you can in both the snatch and the clean & jerk. In competition (again, in theory), weightlifting is a group of people all trying to lift as much as they can in the snatch and clean & jerk, and whoever lifts the most on that particular day is the winner.

Of course, it can’t be that straightforward. “Lifting more weight” isn’t just dependent on the athletic ability of an athlete. Generally, bigger people can lift more weight. Age, gender, height, body type, flexibility, and even length of arms and legs also come into play. In short, the only constants in weightlifting are the weight on the bar and gravity itself. Everything else is variable.

When it comes to competition, The Powers That Be decided that age, gender, and bodyweight were going to be the only variables worth categorizing. Those with optimum height, body type, flexibility, and extremities would ultimately rise to the top anyway. With multiple age categories and weight classes, the question then becomes, “how do we eliminate all of the variables and figure out who is the best overall weightlifter?”

In numerical terms, if a 50kg man and a 100kg man each have a total of 50kg, logic tells us that pound for pound (or kilo for kilo), the 50kg man is stronger because he’s lifting his bodyweight, whereas the 100kg man is only lifting a half of his bodyweight. But what if the 50kg man totals 178kg, and the 100kg man totals 303kg? And what about the 130kg man totaling 323kg? Can you do that math in your head? Who is the strongest now? 

Enter the Sinclair Formula, a mathematical equation designed to figure out who is the best male or female lifter, across any age group and weight class, during the current Olympic cycle.

Developed by Dr. Roy Sinclair in 1978, Sinclair developed his formula based on the question “how much more weight could an athlete lift if he weighed more?” Prior to 1978, other methods for equalizing strength were in place, but Sinclair’s formula stuck and got it recognized by the International Weightlifting Foundation.

The Sinclair Total is calculated by taking an athlete’s total (combined max snatch and clean & jerk) and multiplying that number by the Sinclair Coefficient. Since this is Explain Like I’m Five, a “coefficient” is a mathematical term you might remember from algebra that basically just means “a constant number by which a variable is multiplied.” In weightlifting jargon, the coefficient is the number that Sinclair came up with to represent an athlete’s bodyweight, and the variable is the athlete’s weightlifting total. You can find the current male Sinclair coefficients here and female coefficients here.

Using our above example, our 50kg male has a Sinclair coefficient of 1.713308. The math looks like:

178kg (total) x 1.713308 = 304.969 (Sinclair Total)

The 100kg male’s coefficient is 1.112602.

303kg (total) x 1.112602 = 337.118

The 130kg’s coefficient is 1.030222.

323kg (total) x 1.030222 =  332.762

The strongest man by this definition, is the 100kg man.

But how is the Sinclair Coefficient calculated to begin with? Sadly, there’s no Explain Like I’m Five to explain this, even an Explain Like I Took a Math Class Once and Sort of Recognize Those Symbols doesn’t really cut it. Basically, the answer is statistics, logarithmic functions, and general math. For the curious nerds, the actual formula is {\displaystyle 10^{A({\log _{10}{(x/b)}})^{2}}}, where is the lifter’s bodyweight, is the current world record holder’s body weight in the heaviest current weight class, and is the coefficient for this Olympic Cycle.

For the rest of us who can’t understand, the specifics don’t matter. This is a prime time to just understand that it works and not think too much about it.

The Sinclair Coefficient differs for each weight class and is consistently updated based on current world records. Therefore, the Sinclair Coefficient can’t really be used to compare relative strength from athletes from different parts of history. It is used, however, to determined the “Best Lifter” of a weightlifting meet. It’s possible for an athlete to not win the overall prize but to still be considered the strongest athlete at the competition based on his/her Sinclair Total. We saw this dramatically go down during the 2016 Olympic Trials, when Mattie Rogers failed to qualify for the Olympic team but still was awarded Best Lifter based on the Sinclair Total.

The internet has gifted us with an array of Sinclair Total calculators, but we default to the IWF’s calculator because we know it’s properly updated. Even for everyday athletes, the Sinclair Total is a great way to see how much you’d theoretically lift if you were gigantic, or if you want to compare your relative strength to today’s top lifters. It’s also great if you’re in a competition with your friends and need to find out who is the strongest, once and for all!

Featured Image: International Weightlifting Federation (@iwfnet)