I did work it out in my study that actually reading three chapters a day in the Old Testament allows you to read through the OT once every year.
A NEW PLAN:
The old rule of reading three chapters a day and five chapters on Sunday will allow you to read through the entire Bible in one year. Try it!
Also, I personally have found taking the Bible that you choose to read and looking at the number of pages and dividing them by the amount of days you want to read in order to finish it, you can then read that many pages each day. This will give you a uniform reading approximately that same amount of time each day in your reading.