Sap sugar content vs syrup

[MapleMike]

Question.
Is there a formula based on sap sugar content equals a certain syrup yield.
I've been boiling some sap w/3.5% sugar content and it seems like I'm getting end of season results.

Thanks for your help in advance.
Mike

[wnybassman]

The number 86.

86 divided by 3.5 = 24.6 which gives you a 24.6:1 sap to syrup ratio

I wish my end of the season results were like that.

[CitySlicker]

the rule of 86:

http://maple.dnr.cornell.edu/FAQ.htm

"Let’s say you have trees that average 2% sugar content and you have trees large enough for two taps per tree. Using the "Rule of 86," you know that the number of gallons of sap you need to produce one gallon of syrup is equal to 86 divided by the percent sugar of 43 gallons of sap. "