This gets a bit confusing. We need 30mil between boards to get the router bit in. But, you can save some money by determining the overall square that your boards fit into.
Your board is 1"x1.6". Normally, this would be 2 square inches.
If you need 5 boards, add .030 to one dimension and multiply by 5.
1.6 + 0.030 = 1.630 * 5 = 8.15" - round up to 9". The total usage is 1x9" or 9 square inches saving you 1 square inch. A little savings in this small example, but it can add up!