Why Use the HDScores Health Scores App

Let us Help You Feel Safe When Eating Out.


Research shows that increasing awareness and providing access to consumers on health inspection scores, reduces the amount of food borne illness hospitalizations per year. HDScores mission is to hold establishments cleanliness to a higher standard, which in return will enhance the diner’s overall experience.

The Problem

The majority of health inspection reports are traditionally about a moment in time when a health inspector walks into a restaurant. Does that establishment meet the required standard, right then and there? In an extreme case, that restaurant could be immediately closed down, yet some Health Departments allow restaurants that fail up to two weeks to address their shortfalls and then be re-inspected. So when every restaurant around you has a passing grade, how do you know which ones have a structured hygiene process that is robust, proven and safe in comparison to the ones that papered over the issues to pass the inspection?

The Solution

We wanted to develop a way to solve this problem; health safety is not about a moment in time but about continuous good practices that run to the core of an establishment. Accordingly, we developed a percentage score from the best (100%) to the worse (0%). To calculate this we take a two-year view of a restaurant’s operation, using local health inspection data to determine violations, demeriting the score based on number, severity and repeated offenses. To encourage continuous improvement practices and to recognize that every restaurant can have a bad day, a weighting is placed on the score that promotes current actions over historical events to create a raw score. We then wanted to make it local, so that everyone in everyday dining decisions can use it. To do this, we rank the raw scores of each restaurant within a jurisdiction, be it city or county, against each other so that the consumer can differentiate between all the passing grades and can choose the safest restaurant with the highest score and avoid establishments that just make the grade with lower scores. Using this process, we create the HDScore, which is applied using the same formula worldwide, solving the problem of which restaurant is the safest to eat at and recognizing the best run restaurants in your area that do more every day than just pass.


To the average person on the street, the methods we use to determine the creation of an HDScore may be too complicated to understand. When we make this statement, it can often lead to suspicion that we don’t have a validated, scientifically proven and robust means of producing the score. To all those doubters, mathematician’s, engineers, scientists, health inspection professionals and restaurant owners out there who are curious or want to understand further the following is the mathematical process we follow to calculate an HDScore:

Step 1 – Calculate each inspections demerit points.

Each inspection report is given a demerit point score based on the number of violations and the severity of each. Every violation per inspection is assigned a demerit value as following:

1 point per violation

+1 point if the violation is repeated (a repeat violation from a prior inspection)

+1 point if the violation is critical or priority (signifying the health department determined this violation to lead to foodborne illness)

-0.5 point if the violation is corrected on site (corrected during the inspection process)

+0.5 point if the violation is priority foundation (signifying the health department determined that this violation if repeated, may lead to foodborne illness)

– Exception: If the jurisdiction does not report individual violations, the jurisdictional score minus 100 is used as the demerit points

– Exception: If the jurisdiction does not report individual violations or jurisdictional score based on 100, the letter grade is used assigning an A as 0 demerits, B as 10, C as 20, D or less as 30

Step 2 – Calculate weighted average demerit points for each establishment

The average demerit score for an establishment is calculated by using an exponential decay average weighting giving a half-life of the exponential decay (50% weight) to be at 1 year from the latest inspection. This is represented by the following, standard statistics equation:

The summation is over all inspections for the establishment. Delta D is the number of days from the latest inspection, Demerits is the demerit points for that inspection.

Step 3 – Calculate percentage between best and worst in health jurisdiction

For each health jurisdiction, the best and worst average demerit points set 100% and 0% respectively. Each establishment is assigned a percentage score (same as grading on a curve in college) based on this. The equation looks like this:

where AD establishment is the establishment’s average demerits (calculated in #2), ADmin is the lowest average demerits for any establishment in the health jurisdiction, and ADmax is the maximum demerit points for any establishment in the health jurisdiction


Note: The percentages only compare establishments within their given health department/health jurisdiction to ensure the comparison is fair based on reporting standard, food regulation deviations, etc.

Our mission is to protect, promote and improve cleanliness amongst establishments.


Download our HDScores App now!


#1 App for Restaurant Health Inspection Scores Nationwide.



The HDScores App will allow you to “favorite” establishments and receive notifications on the their newest health inspection ratings. You will be able to search by your current location as well as nationwide.


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