Here is an site sponsored by Harvard University with tests, designed by research psychologists, that claim to determine whether you are prejudiced, consciously or unconsciously, in matters of race, gender, sexuality, age, body size and so on. You are asked to sort terms and images into categories, and the test measures your speed and rate of errors. From that, the site calculates your level of prejudice.
For instance, my test results indicated a slight preference for young people over old people.

However, they showed no preference between straight people and gay people

or between thin people and fat people

. I'm not sure I totally trust the tests -- I think you get better at doing them as you go along, and that affects your results (I did the old/young one first). Still, it's an interesting exercise, and supposedly scientific.
https://implicit.harvard.edu/implicit/