Depends on how many candles you want to make.

I personally just break off whatever I think I'll need (there's a "science" to knowing but I'm too lazy to get out a scale and blah blah blah. lol.). If I have some much left over (which is always your goal), I just make a little jar and don't put a wick in it. I use it on my candle warmer at home. That also lets me know if the scent is strong enough or not. If not... well... time to start over. lol.