While the size of your emergency fund will vary depending on your lifestyle, monthly costs, income, and dependents, the rule of thumb is to put away at least three to six months’ worth of expenses. This amount can seem daunting at first, but the idea is to put a small amount away each week or two to build up to that goal. You may also want to consider adjusting the amount based on your bill obligations, family needs, job stability, or other factors.