Expected length of roller chain
Applying the center distance between the sprocket shafts and the amount of teeth of each sprockets, the chain length (pitch amount) might be obtained in the following formula:
Lp＝（N1 ＋ N2）/2＋ 2Cp＋｛（ N2－N1 ）／2π｝2
Lp : Total length of chain (Pitch variety)
N1 : Quantity of teeth of compact sprocket
N2 : Number of teeth of big sprocket
Cp: Center distance among two sprocket shafts (Chain pitch)
The Lp (pitch variety) obtained from the over formula hardly turns into an integer, and usually contains a decimal fraction. Round up the decimal to an integer. Use an offset hyperlink if the amount is odd, but select an even variety around achievable.
When Lp is established, re-calculate the center distance between the driving shaft and driven shaft as described during the following paragraph. In the event the sprocket center distance can’t be altered, tighten the chain working with an idler or chain tightener .
Center distance between driving and driven shafts
Naturally, the center distance among the driving and driven shafts has to be far more compared to the sum from the radius of each sprockets, but generally, a suitable sprocket center distance is considered to get 30 to 50 occasions the chain pitch. However, in case the load is pulsating, 
twenty instances or much less is correct. The take-up angle among the tiny sprocket as well as the chain has to be 120°or extra. If the roller chain length Lp is given, the center distance involving the sprockets can be obtained through the following formula:
Cp＝１/4Lp－(N1＋N2)/2+√(Lp－(N1＋N2)/2)^2－2/π2（N2－N1）^2
Cp : Sprocket center distance (pitch quantity)
Lp : General length of chain (pitch quantity)
N1 : Amount of teeth of small sprocket
N2 : Amount of teeth of massive sprocket
