Michigan property tax estimation tool
Last year I received a nasty surprise when my Westland, Michigan mortgage jumped $143/month. This was due to the new property tax assessment. Unfortunately this happened just after I re-signed my current tenant for another year.
I just found this tool to help you determine Michigan property tax values. The SEV (state-assessed value) is half the value of the house. Make sure you are putting in either 1/2 your purchase price or 1/2 the ARV.
https://www.michigan.gov/taxes/0,4676,7-238-43535_43540---,00.html
It's critical you put this in your numbers when analyzing Michigan deals. Investment property millage rates are higher compared to principal residence rates. Moreover, mortgage calculators are flat-out wrong if you're trying to estimate payments. The taxes in Michigan will easily be 2-3x higher compared to their general estimates.