You only really need about 1-1.2g of protein per lb of
lean mass... so it won't be 170lbs. If you're at 10% BF it will be 170-17= 153lbs, therefore @ 1g per lb you'll need 153...
Some people say 2g of protein per lb, but unless you're training like a mofo and a huge proper bodybuilder I don't think there's a need, and that's a fairly hard number to achieve unless it's your life IMO. I get by fine with 1g per lb, and I'm over 15st and low BF - and rather solid looking
I don't count calories, I just know what foods to eat, I don't eat a lot of bread, I don't drink fizzy drinks, or alcohol (beer in particular), sweets or chocolate, or fast food or greasy/fatty foods. I grill my meat, steam my veggies and eat a well balanced diet. I do probably eat slightly over the average kCals per day of a man, but it hasn't stopped me putting on over a stone in 16 months whilst keeping my bodyfat low.