How much money can I expect from a tax exemption?

It's my first year in a new job and I am currently claiming 1 on my W4. My tax return was a little smaller than I had hoped this year, so I was thinking of claiming 0 to give me a bigger "bonus" next year. How much money can I expect to disappear from my paycheck which is usually around $1250 after pre-tax deductions, and about $950 after taxes now?