Amortization schedule needed /seller financing

[Zk Lani]

Hello everyone, hope you’re all safe and healthy.

Does anyone have an excel sheet or a software they can share for amortization schedule that reflects monthly change in principal/interest payments based on extra monthly principal payments I’ve been putting? I bought a property 4 months ago with seller financing with a 2 year balloon. I’ve been paying extra principal every month and working on refinancing this year to pay off the seller. I couldn’t find online an amortization schedule where it reflects the monthly P/I based on the extra principal payments. I’ve been putting good chunk of extra principal each month so would help to know exactly what my equity is that I’ll be refinancing.

Thanks a bunch!

ZK