Americans are getting away with murder.

A new FBI report found that roughly 40 percent of the nation’s slayings went unsolved last year.

The bureau looked at 2017 crime and arrest data from 16,000 law enforcement agencies across the country and found that only 61.6 percent of reported murders were “cleared.”

The FBI considers a murder case cleared when a person is arrested, charged and turned over to courts, or when offenders are identified but cannot be arrested because they died or can’t be extradited.

That leaves 38.4 percent of the 15,657 murders reported nationwide unsolved — 6,012 in all, according to FBI data.

Law enforcement’s success rate in the area has been slipping for a decade, from a high of 66.6 percent clearance in 2009.

Meanwhile, the country’s murder rate has climbed over the same period, from 5 per 100,000 people 2009 to 5.4 in 2017.

New York state’s 2017 murder rate was far lower than other states often perceived as safer. About 2.8 out of every 100,000 residents in New York were killed last year. By comparison, Ohio’s rate was 6.1, Alabama, 8.3, Missouri, 9.8 and Washington, DC, 16.7.

Meanwhile, big-city cops are generally solving murders better than their Mayberry counterparts.

Police in cities with more than 1 million residents cleared 69.1 percent of murders in 2017, compared to 57.1 percent in cities with 500,000 to 999,999 residents. Smaller cities didn’t fare much better, and only municipalities with 25,000 to 49,999 residents got close to big-city success rates with 63.5 percent of murder cases cleared.

New York saw 292 murders or non-negligent-manslaughter cases in 2017, a little over half the 523 murders reported in 2008, data show.

The NYPD cleared 85.3 percent of its murders — 249 out of 292.

Murders accounted for just 1.4 percent nationally of the eight “index crimes” that the FBI tracks, which include homicide, forcible rape, robbery, burglary, aggravated assault, larceny, motor-vehicle theft and arson. Aggravated assaults comprised 65 percent of violent crimes, while robbery was 25.6 percent and rape 8 percent.

The Big Apple had the lowest overall crime rate out of the nation’s 25 largest cities — with a combined total of 1,987 homicides, forcible rapes, robberies, burglaries, aggravated assaults, larcenies, motor-vehicle thefts and arsons per 100,000 people.