Tithing (10% donation), as many mentioned, is not required, but regular giving is feasible, especially in light of programs for Electronic Funds Transfer.
And, as others have said, the ability to give (as far as amount goes) is dependent on the situation of each giver.
Its not how much, but with what spirit we give.
On a side note, long ago I realized that when there was a need, and I told myself I just couldn’t afford to give, that if I gave anyway, it presented very little hardship on me, in both the short and long run financial picture.
Another idea (and again, amount is not important), is to make your donation the first “bill” you pay.
My method (and again, I may be blessed, so the amount or percentage is not important) is to add all my gross (before deductions) income, divided it by 52 (weeks in the year), then divide by 40 (hours in a work week). This equates to the first hour (gross) pay I earn for the week. And this becomes the basis for my giving for the year…and then I adjust it each year when my gross income is calculated for the passing year.
So, technically not tithing, but it is a manageable donation of “first fruits”.