Apps for budgeting and personal finance do a good job of tracking your money as you earn and spend it. Some also have excellent debt calculators that help you figure out how to pay off your debts.

Each debt calculator is a little different. Some suggest a specific method for paying down debt, while others are simulators that let you see how your total amount paid will decrease if you increase your monthly payment.

Here are a few useful calculators and some guidance about what makes them different.

A Straightforward Plan: Bankrate

Bankrate’s free debt payoff calculator gives you a timetable for paying off each of your debts. You enter as many debts as you want to include, their interest rates, total loan amounts, and other details. You also enter any new income you expect to receive, such as an annual salary increase or windfall, and the amount that you can put toward your debts. The calculator then generates one payment table for each debt showing how much to pay each month until the debt is cleared.

Bankrate prioritizes paying off the debt with the highest interest rate first. Once your first debt is paid off, the money you would have put toward it is diverted to your other monthly payments. In other words, as you eliminate debts, the monthly payments on your other debts increase until they, too, are paid off.

Who should use it? Bankrate’s calculator works for people who have multiple debts, and the total monthly minimum payments are within their financial reach. If that’s you, then you’ll get a crystal clear plan—with a timeline—for getting rid of all your debts.

Where it comes up short. This calculator assumes that paying off your debts by clearing the one with the highest interest rate first is in your best interest. That’s not true for everyone. You might have other options, such as consolidating credit card debt to a new card with a 0 percent introductory rate or filing for bankruptcy. Bankrate also doesn’t take into account other personal finance concerns, like other uses of monthly funds that free up once you pay off your first debt—Bankrate tells you to put that money toward your next-highest-interest debt. You might be better off putting it toward retirement savings or an emergency fund.

Big-Picture Guidance: NerdWallet

NerdWallet’s free debt load calculator determines your debt load as a percentage of your income. The resulting debt load is classified as smaller (less than 36 percent), larger (37–42), or overwhelming (43 percent or more). Based on the outcome, NerdWallet suggests a method for eliminating your debt, which you read about in an educational article below the results.

Who should use it? This calculator helps you get a big-picture sense of your debt. If you have a lot of debt, it’s useful for ruling out (or ruling in) the option of declaring bankruptcy.

Where it comes up short. It’s not great at analyzing the finer details of your debt. For example, in the setup, there’s no line item for student loans or a mortgage, much less the exact interest rate you pay on loans. The results are a rough guide rather than a personalized strategy.

Automated Inputs: WalletHub

When you sign up for WalletHub (free) and connect your financial accounts, the app pulls real information about how much money you owe and your payment history. Its debt payoff plan is a calculator that lets you play with the numbers to see what would happen if you increased your monthly payment. How much faster can you clear the debt? How much will you save in interest? You can quickly see the difference between increasing your monthly payment by, say, $50 versus $150.

Who should use it? This calculator is for WalletHub users who have connected their financial accounts. It’s most useful for people who can afford to pay more than the monthly minimum on their debts.