DISCLAIMER
This online calculator estimates lorythmic swingweight of a club based upon a simplified version of the swingweight formula that allows you to approximate the function of a true swingweight scale using a tape measure and digital scale.
The formulla is not an approximation but corresponds to how a swingweight scale functiones. The "problem" with this method is measuring the balance point with enough accuracy. A swingweight scale is just more accurate.
Accurate swingweight calculations require separate measurement of grip weight, shaft weight and head weight before assembly.
Not even close, If you don't know the centre of gravity (balance point) of all those components that method will be an estimate.
Funny enough the Lorythmic scale has 2 definitions : one swingweight being 50 grams or 1.75 ounce; D-0 is 121 swingweights in grams and 122 swingweights in ounces (6050 gram-inch = 213.5 ounce-inch). So who cares if a club measures D-1.5 or D-1.1; most people do not even feel the difference of a whole swingweight.
The formulla is simple enough :
weight in ounce x (balance point in inch - 14") /1.75 - 82 or weight in grams x (balance point in inch - 14")/50 - 81 gives the Lorythmic swingweight were the first digit is replaced by the corresponding lettter in the alfabet.
A swingweight scale on the basis of a digital gram scale does that last calculation mechanicly (put the club on a -14" fulcrum, measure 10gram @ 5" = /50, calibrate the scale to 300g @ 13.5" = -81 swingweights"): again replace the first digit of the read-out by the corresponding letter in the alfabet to have the Lorythmic swingweight.
