Hey all! We're doing good out here on our financial goals, and making a lot of progress!

We are looking to fine-tune the payoff of a property we're selling on contract to another buyer.

I need an amortization calculator that rolls out a full monthly amort schedule, and then lets me put in variable additional principal payments for different months, and then re-calculates from that point forward. The online calcs I'm finding only let me put in a standard monthly additional payment, and/or a one time or regularly-scheduled balloon payment.

I need to do scenarios with lots of variables, and see what will work best for both us and the new buyer. For example, we are in year 7 of the 30-yr mortgage, we've paid some extra thus far, and I need to run scenarios for what if we bump the monthly payment by $1000 for March, April, and May of next year, then a $10k balloon in July, then bump monthly payment by $1500 each month thereafter to payoff - what payoff date does that give me. (for example)

Thank you for any online calc suggestions that can do this!

MouseBandit