How to Read Car Safety Ratings Before You Buy

What car safety ratings tell you

Car safety ratings measure how well a vehicle protects you in a crash. Two independent organizations test vehicles and publish the results: the National Highway Traffic Safety Administration (NHTSA), a federal agency, and the Insurance Institute for Highway Safety (IIHS), a nonprofit funded by insurance companies. Both crash-test new models and rate them on a scale. The ratings are free to look up before you buy, and they differ because each organization tests different crash scenarios and weighs the results differently.

A safety rating is not a pass-or-fail judgment. It tells you how a specific model performed in controlled crash tests at a specific speed. A car with a lower rating is not necessarily unsafe to drive — it simply absorbed impact differently in those particular tests than a car with a higher rating did. Real-world crashes vary widely, and no test can predict every scenario.

Key Takeaways

• NHTSA rates vehicles on a five-star scale across four crash types; IIHS uses a different scale and tests different scenarios, so the two organizations' ratings are not directly comparable.
• You can look up ratings for any vehicle model year on NHTSA.gov or IIHS.org at no cost, using the vehicle's year, make, and model.
• A safety rating measures crash-test performance only and does not account for how often a vehicle is involved in crashes on the road or how likely it is to be stolen.
• Newer model years are tested more often than older ones, so a 2024 model may have ratings while a 2015 model of the same car may not.
• Both organizations publish ratings for most vehicles sold in the United States, but some specialty or imported models may not have been tested.

NHTSA ratings and what the stars mean

NHTSA tests every new vehicle model and publishes results on safercar.gov. The agency rates each vehicle on five separate tests: frontal crash, side crash, rollover, seat belt use, and crash avoidance. Each test receives a rating of one to five stars, with five stars being the best. NHTSA also calculates an overall rating, which is a weighted average of the five categories.

The frontal crash test simulates a head-on collision at 35 miles per hour into a fixed barrier. The side crash test hits the vehicle's side at 38.5 miles per hour with a movable barrier. The rollover test does not involve an actual crash — instead, NHTSA measures the vehicle's resistance to tipping based on its weight distribution and suspension. The seat belt and crash avoidance ratings measure whether the vehicle has modern safety features like automatic emergency braking or seat belt reminders.

A vehicle that scores five stars across all categories is rare. Most vehicles score three or four stars in some categories and fewer in others. A three-star rating means the vehicle performed at an average level for its class; two stars means below average; one star means well below average.

IIHS ratings and how they differ from NHTSA

IIHS uses a different testing method and a different rating scale. Instead of stars, IIHS rates vehicles as "Good," "Acceptable," "Marginal," or "Poor" in each crash test. The organization tests frontal offset crashes (where the vehicle hits a barrier at an angle rather than head-on), side crashes, roof strength, and seat belt effectiveness. IIHS also tests crash avoidance features separately and rates them as "Superior," "Advanced," or "Basic."

IIHS awards a "Top Safety Pick" designation to vehicles that score "Good" in all crashworthiness tests and have superior crash avoidance technology. This is a competitive award — not every vehicle can earn it, and the criteria change each year. A vehicle that earns a Top Safety Pick from IIHS may not score five stars across the board from NHTSA, and vice versa, because the two organizations test different crash angles and measure different outcomes.

IIHS testing is more expensive and more selective than NHTSA testing. The organization does not test every model year or every trim level. If a vehicle model has not changed significantly from the previous year, IIHS may not retest it. This means some vehicles have NHTSA ratings but no IIHS ratings, or ratings that are several years old.

How to find ratings for a specific vehicle

To look up NHTSA ratings, go to safercar.gov and enter the vehicle's year, make, and model. The site will show you the star ratings for each crash test, the overall rating, and a detailed breakdown of how the vehicle performed. You can also see which safety features the vehicle has, like airbags and stability control.

To look up IIHS ratings, go to iihs.org and use the "Ratings" search tool. Enter the year, make, and model. If the vehicle has been tested, you will see the ratings for each crash scenario and the crash avoidance rating. If the vehicle has not been tested or was tested several years ago, the site will tell you that.

Both sites let you compare two vehicles side by side. This is useful if you are deciding between two models in the same price range. Keep in mind that a newer model year may have different ratings than an older one, even if it is the same make and model, because manufacturers update safety features and structure over time.

What safety ratings do not measure

A safety rating tells you how well a vehicle absorbs impact in a controlled crash test. It does not tell you how often that vehicle is involved in crashes on real roads, or whether drivers of that model tend to drive more or less safely than drivers of other models. Some vehicles with lower safety ratings are involved in fewer crashes because their drivers are more cautious; some vehicles with higher ratings are involved in more crashes because their drivers take more risks.

Safety ratings also do not measure theft risk, reliability, or repair costs. A vehicle with excellent crash-test ratings may be expensive to repair or may have a history of mechanical problems. Conversely, a vehicle with lower ratings may be affordable to fix and very reliable. Safety ratings are one piece of information to consider when buying a car, not the only piece.

Ratings also do not account for how a vehicle performs in crashes at speeds higher than the test speed, or in types of crashes that were not tested. A vehicle that scores well in a frontal crash test may not perform as well in a T-bone crash or a rollover, because those scenarios involve different forces and angles.

Older vehicles and discontinued models

NHTSA and IIHS test new models continuously, but older vehicles may not have current ratings. If you are buying a used car from 2015 or earlier, you may find ratings from the year it was manufactured, but those ratings may not reflect safety improvements made in later model years of the same vehicle.

If a vehicle model has been discontinued, you can still find its ratings on both sites by searching for the year and model. The ratings remain available as a historical record. However, discontinued models are not retested, so the ratings reflect the vehicle as it was when production ended, not as it might perform with modern safety technology.

Some vehicles, particularly imported models or specialty vehicles, may not have been tested by either organization. In those cases, you can look for safety information from the manufacturer or from consumer reviews, but you will not have standardized crash-test ratings to compare.

How to use ratings when shopping for a car

Safety ratings are most useful when you are comparing vehicles in the same class or price range. A midsize sedan with a four-star overall rating is not necessarily safer than a compact car with a three-star rating, because the two vehicles are tested separately and their sizes affect how they perform in crashes. Heavier vehicles tend to score higher in frontal crashes because they have more mass to absorb impact, but lighter vehicles may score higher in rollover resistance.

If you have narrowed your choice to two or three specific models, use the ratings to see which one performed best in the crash scenarios that matter most to you. If you drive mostly on highways, the frontal crash rating may be most relevant. If you drive in urban areas with a lot of side-impact risk, the side crash rating may be more important. If you have a long commute on rural roads, rollover resistance might be a priority.

Remember that a vehicle's safety also depends on how you drive it, how well you maintain it, and whether you use safety features like seat belts and child car seats. A vehicle with excellent ratings will not protect you if you do not wear a seat belt, and a vehicle with lower ratings may still be safe if you drive defensively and keep it in good repair.

Frequently Asked Questions

Can I trust one rating system more than the other?

Both NHTSA and IIHS are reputable organizations, but they test different crash scenarios and use different scales. NHTSA tests more vehicles and publishes results for nearly every new model. IIHS tests fewer vehicles but uses more rigorous crash angles. Neither is "better" — they measure different things. Looking at both ratings gives you a more complete picture than relying on one alone.

What does a three-star rating mean?

A three-star NHTSA rating means the vehicle performed at an average level for its class in that particular crash test. It is not a failing grade. Most vehicles on the road score three or four stars in various categories. A three-star rating simply means other vehicles in the same class performed slightly better in that specific test.

If a vehicle has not been tested, is it unsafe?

Not necessarily. Some vehicles have not been tested because they are new to the market, imported from another country, or produced in small numbers. Lack of a rating does not mean the vehicle is unsafe — it means the testing organizations have not yet crash-tested that particular model. You can look for safety information from the manufacturer or consumer reviews instead.

Do safety ratings change over time?

Ratings do not change for a vehicle that has already been tested, but new model years of the same vehicle are tested separately and may receive different ratings. Manufacturers often update safety features and structure from year to year, so a 2024 model may have higher ratings than a 2023 model of the same car. Always check the rating for the specific year you are considering.

Should I only buy a vehicle with five-star ratings?

Five-star ratings are excellent, but they are not the only factor in choosing a safe vehicle. Consider your driving habits, the vehicle's reliability, your budget, and how well the vehicle fits your needs. A three or four-star vehicle that you maintain properly and drive carefully may be safer overall than a five-star vehicle that you neglect or drive recklessly.