Understanding NHTSA 5-Star Safety Ratings: What the Stars Mean

What Is the NHTSA 5-Star Safety Rating?

The NHTSA 5-Star Safety Rating system is the U.S. government's vehicle crash test program, officially called the New Car Assessment Program (NCAP). It has been testing vehicles and publishing ratings since 1978, making it one of the longest-running vehicle safety programs in the world.

The program evaluates how well vehicles protect occupants in crash scenarios. Results are published as star ratings, with 5 stars being the highest score and 1 star being the lowest. These ratings help consumers compare the safety of different vehicles when making purchasing decisions.

How the Tests Work

NHTSA conducts three types of crash tests:

Frontal Crash Test

A vehicle is driven head-on into a rigid barrier at 35 mph. This simulates a frontal collision between two identical vehicles, each traveling at 35 mph. Instrumented crash test dummies in the driver and front passenger seats measure the forces experienced during the impact.

The test evaluates:

• Head injury risk
• Chest compression
• Femur (thigh bone) force

Separate ratings are given for the driver and front passenger because the forces can differ between the two positions.

Side Crash Test

A 3,015-pound barrier moving at approximately 38.5 mph is driven into the side of the test vehicle. This simulates being hit in the side by another vehicle at an intersection — one of the most dangerous types of collisions because there is relatively little structure between the occupant and the impacting vehicle.

The test evaluates:

• Torso injury risk
• Pelvic injury risk
• Head injury risk

Separate ratings are given for the front seat occupant and rear seat occupant.

Side Pole Test

The vehicle is propelled sideways at 20 mph into a rigid pole, simulating a vehicle sliding sideways into a tree or utility pole. This type of crash concentrates the impact force on a very small area, making it extremely dangerous.

Rollover Resistance Test

Unlike the other tests, rollover resistance is not a crash test. Instead, NHTSA uses a measurement called the Static Stability Factor (SSF), which is based on the vehicle's track width (the distance between left and right tires) and its center of gravity height.

Taller, narrower vehicles like SUVs have a higher rollover risk than lower, wider vehicles like sedans. The rollover rating also incorporates a dynamic maneuver test.

What the Stars Mean

The star ratings translate to statistical risk percentages:

Frontal Crash and Side Crash:

• 5 stars = 10% or less chance of serious injury
• 4 stars = 11% to 20% chance of serious injury
• 3 stars = 21% to 35% chance of serious injury
• 2 stars = 36% to 45% chance of serious injury
• 1 star = 46% or greater chance of serious injury

Rollover Resistance:

• 5 stars = Less than 10% rollover risk
• 4 stars = 10% to 20% rollover risk
• 3 stars = 20% to 30% rollover risk
• 2 stars = 30% to 40% rollover risk
• 1 star = Greater than 40% rollover risk

The Overall Rating

The overall safety rating is a combined score that takes into account all individual test results. It provides a quick way to compare vehicles, but you should also look at the individual test ratings because a vehicle might score 5 stars overall while having a 3-star rollover rating.

How to Use Safety Ratings

When shopping for a new car: Compare the safety ratings of vehicles in your price range and segment. A 5-star rated compact SUV offers better crash protection than a 3-star rated one.

When comparing different vehicle types: Be aware that NHTSA ratings are most meaningful when comparing vehicles of similar size and weight. A 5-star subcompact car is tested against the same barrier as a 5-star full-size truck, but in a real collision between those two vehicles, the laws of physics favor the heavier vehicle.

When checking a used car: Use our VIN decoder to look up the safety rating for any vehicle. This is especially useful when considering older vehicles where you might not remember or know the original safety scores.

Limitations of Safety Ratings

Safety ratings are valuable but have limitations:

• Ratings only compare within a vehicle's weight class — A 5-star small car is not necessarily safer than a 4-star large SUV in a real-world collision between the two.
• Not all vehicles are tested — NHTSA selects vehicles for testing based on sales volume and other factors. Some models, especially low-volume ones, may not have ratings.
• Tests use standardized scenarios — Real-world crashes happen at different speeds, angles, and conditions than laboratory tests.
• Ratings do not account for active safety features — Technologies like automatic emergency braking, lane keeping, and blind spot monitoring can prevent crashes entirely, but they are not reflected in crash test ratings.

NHTSA vs. IIHS

NHTSA is not the only organization that tests vehicle safety in the United States. The Insurance Institute for Highway Safety (IIHS) also conducts crash tests and publishes ratings. The two programs use different test procedures and scoring systems:

• NHTSA uses a star system (1-5 stars)
• IIHS uses a scale of Good, Acceptable, Marginal, and Poor

The programs complement each other. A vehicle that scores well on both NHTSA and IIHS tests provides strong evidence of good crash protection.

Check Your Vehicle's Rating

Use our VIN decoder to look up the NHTSA safety rating for any vehicle. Enter the VIN and scroll to the Safety Ratings section to see the overall, frontal crash, side crash, and rollover ratings with the full star display.