I don't use Calvert, but I wanted to let you know of a great website called Homeschool Reviews.
You can find information and reviews of MANY different curriculums there ( including Calvert.)
They also have forums - where you can ask questions about different curriculums. It really helped me a lot when I was researching all of the different choices.

(Hope that helps!)
Michelle W.

Hi. I am Denise and we live in las vegas. We used calvert for 4Th grade and are doing 5th grade now. Calvert is very thorough. The textbooks are what most schools use and we covered every page of every book! You can test free from Calvert to see what grade level to start with. They have a program called scholastic which helps to build more on the foundations and you may want to use that to get a good base for the future. I think it has less writting assingments and a few less books to read than the academic program. We like calvert. There is alot of work. We take almost a full year to do the work in order to cover it comfortably. The best thing about the program is that you can talk to an educator about any material that you need help with. They are great. The lesson manual lays out what to do for each day with instructions of a sentence to a paragrah on extra info to help you understand what they are to do. We dont use the service(ATS) that has you mail in the tests to be graded. Nevada doesnt require it so I just grade the tests myself. We buy the test series because the ATS tests that come with the program dont come with the answers and the test series tests have answers with the tests. These cost extra-$65 or so. They only drawback is not having someone else to evaluate our compositions. The cons are the: answer key sometimes has a wrong answer, there is alot of work that they have to cover and it will take 3-6 hours each day depending on the grade(it is hard to stay home and not be distracted by all the stuff that pulls us away from the school but there is no point in buying something if they arent going to do it)and we stuggle with this daily so dont feel bad about trying to stay on track. The material is geared to the average student and isnt intimidating. There are some fun things in 4th grade history that keeps the kids having fun. Im glad we use it because it less stress for me as everything is planned and the only books you may need to buy are a handwritting and health book. You dont have to do everything all the time but its all there if the kids need to learn it. It is very school like. Hope this helps a little.