Have a recipe emergency HELP!!!

Trying to make key lime pie for T dinner tomorrow. I have the recipe and all the ingredients except I couldn't find any key limes. I know I can use limes and have to adjust the amount of lime juice, but I don't know by how much or even if I use less or more. Can anyone help? I'm trying to get as much done tonight as I can, so it's not soooo much work for me tomorrow, in other words I need help ....like.... yesterday. HELP!!!!!! Please?

From what I researched key limes are smaller and more sour. It says to substitute 1/2 regular lime and 1/2 lemon juice for key limes. Some grocery stores sell a key lime juice for pies (Nellie & Joes brand) )where they keep the Realemon products.

Thanx Stephanie! I must be dense or something, does that mean reduce by half or increase by half? Soundz like since KL are stronger than limes I need to increase by half more. Does that sound right to you? Have I said thank you? Thank you!