I have no idea why my eff is so low please critique what I have done and how is this going to affect my beer overall and abv.

Here is my grain bill for a mack and jacks all grain clone

9.81 british 2 row pale

1.15 crystal 80

1.15munich

.58 cara/pils

total grn bill 12.69

12.69x1.25=15.82qts or 3.96 gallons

I mashed 4gallons @ 155 for 60 min

to figure my sparge I took the equation

12.69 x.20(for absorption) and got 2.53 absorbed this wuoud leave about 1.4 of wort.i wanted 6.5 boil volume so I took 6.5-1.4 and sparged with 5.1 gallons.

I sparged with 2.5 @ 182 then sparged 2.5 @ 170. ( i read that if I split the sparge it would increase my efficency.

I ended up with 6.6 galons of wort preboil it is a 5.5gallon batch.

my og before boil is 1.045 and I used an online efficency calc and it told me my eff was 52.9%.

What the hell?

Why is it so low?

Can I expect my beer to be in the 4% volume range? it shoule be 5 or 6

I figured the recipe for 65 % b/c I brewed my first batch last week and got 66%

please help I am very frusterated

Thanks