A new tool from HelloWallet helps you calculate the right dollar amount for you. Thinkstock By Lisa Gerstner, Contributing Editor From Kiplinger's Personal Finance, July 2015 A sound financial plan begins with stashing a pile of cash that you can tap in case of an emergency. Experts differ on how much you need to set aside, from as little as three months’ worth to as much as a year’s worth of living expenses. How much you need may depend on your personal profile. See Also: Best Ways to Earn More Interest on Your Savings Now, HelloWallet, a developer of personal finance software, has created a tool that can help you nail down the amount that’s right for you. At www.hellowallet.com/emergencysavings, you’ll enter information including your take-home pay, regular monthly expenses, whether you rent or own your home, and your health insurance policy’s annual deductible and out-of-pocket maximum. The tool then estimates the amount of easily accessible savings you should have in the event of a minor emergency, a major emergency or a layoff from work. Starting from the ground up? You can use each figure as an incremental goal toward building your emergency fund. To track your regular monthly expenses, use a budgeting site such as Mint.com so you can link your bank, credit card and other financial accounts. The best place to keep your emergency fund is in a savings or money market deposit account with a high yield and no monthly fee or minimum-balance requirement. (Watch out for fees for leaving the account inactive.) GE Capital Bank, My Savings Direct and Synchrony Bank offer accounts that yield 1.05% without minimum-balance requirements or fees (Synchrony will charge you $5 a month if your balance drops below $30). The trick to successful saving is to pay yourself first; schedule automatic transfers into savings from your checking account after each paycheck arrives.