How do I calculate my efficiency?

I did my second AG on sunday and would like to know how to calcualte my efficiency?
10.00 lb Pale Malt (2 Row) Us
1.00 lb Caravienne Malt
0.50 lb Cara-Pils/Dextrine
0.50 oz Cascade (5 min)
1.00 oz Cascade (20 min)
0.75 oz Columbus (60 min)
1 Pkgs SafAle English Ale


SG 1.064 5 1/8th gallons

im going to dry hop with the remaining half ounce of cascade.

over all an uneventful brew this one came out really boring I learned never brew in the morning when it's to early for beer. My first all grain started at 3 pm and i was drunk by 6. seemed to go a lot faster(swmbo slayer im going to add orange zest to one week prior to kegging )

What was your OG and volume?

IF you have 5 gallons:

65% eff 1.054 OG
70% eff 1.058 OG
75% eff 1.062 OG
80% eff 1.066 OG

Thanks I went back and posted the starting gravity so im at upper 70's hmmm not bad I suppose

Yah, you are around 76%-77%... that is great!