Cheat sheet for doing calculations

[Jessica Petrone]

Y'all- I know there are calculators and I love that. But I'm also old school and neurotic and would like to do my own calculations. I know eventually it'll be like driving and I will get the hang of it. Are there cheat sheets for what the ranges should be for LTV ratio, appraisal and ARV (do they match up??), also when doing calculations, is it rough numbers or are we calculating in the percentage rate and points of the loan? I'm hoping to use a hard money loan for a rehab property and then BRRRR or flip. Are hard money loans usually less than 12 months? And when you refi into a fixed 30 yr, it's a cash out and you pay back the hard money?