If you're self-employed or own a business, you'll have to estimate the personal tax you owe each quarter, which leaves even more room for error. That makes it easy to end up getting a refund. If you're a W-2 employee, you might get a refund if you had a child during the tax year, your deductions were large enough to itemize, or your spouse brought in less income.
If you're paying estimated taxes, there are even more reasons you might get a refund, but they all stem from you paying more than you owe throughout the year. About 64% of tax returns result in a refund, so you're more likely than not to get one this year.