(NEXSTAR) – Tax season isn’t really fun for anyone, but some states’ residents have it harder than others this time of year.

As families around the country collect their paperwork and get ready to file, people in Connecticut, Illinois, Iowa and New Jersey may find themselves with a heftier tax bill than their neighbors in other states.

An updated analysis by MoneyGeek, a personal finance site, evaluates how “tax friendly” each state is by calculating the tax burden on the average citizen. States with low tax burdens earned an A, while those with the highest tax burden earned Fs.

The state that scored worst overall was Illinois, where taxes represent about 13% of a median family’s income.

Unsurprisingly, the states with no state income taxes at all ended up scoring pretty highly. Those eight states are Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, and Wyoming.

But in some of those states, higher sales tax rates or property tax rates are in place to make up for the lower income tax revenue. Tennessee and Washington have some of the highest sales tax rates in the country, the Tax Foundation says.

According to the updated MoneyGeek analysis, the most “tax friendly” state overall was Nevada, where the median family owes about 4% of its income in taxes.

Meanwhile, 13 states earned either a D or F grade for tax burdens. For some of those states, like Oregon, high personal income tax rates are to blame. In others, like Illinois, high property taxes are a major factor. New Jersey, which earned an F from MoneyGeek, residents have a double whammy of high income and property taxes.

The states with the highest top personal income tax rates are California, Hawaii, New Jersey, Oregon and Minnesota, TurboTax reports, but that doesn't necessarily mean people in those states are getting hit hardest in the end. Each of those states has its own complex set of rules of tax credits, deductions and income floors to pay any state taxes at all.

To conduct the study, MoneyGeek looked at how much a hypothetical family would pay in taxes if they were a married couple with one dependent, a gross income of $94,003 (the median national income at the time of research), and a home worth about $320,900 (the median price of a new home). The lower the taxes on this hypothetical average family, the better the grade.

MoneyGeek’s system of grading states on tax burden only holds true for that hypothetical family. A family who just bought a $1.5 million house in California would probably be paying a lot more in taxes, while a single person who earns $40,000 and is a renter in Texas would pay less.

If you haven't filed taxes yet, you've still got time. The federal deadline to file – or request an extension – is Monday, April 15.