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Step 1: Property
Step 2: Mortgage
Step 3: Options
Offset mortgage: how we model it
Interest each period is calculated on max(0, remaining balance − offset balance). The offset balance is assumed constant.
Step 4: Shared ownership (optional)
Tip: results update as you type. We can carry your inputs to the explainer page via URL (no cookies).
Yearly summary
| Year | Start balance | Interest paid | Principal paid | End balance |
|---|
Year boundaries follow your selected payment frequency (e.g. 12 payments per year for monthly).
Show amortization schedule (first 24 periods)
| Period | Payment | Interest | Principal | Balance | Effective principal |
|---|
Offset balance assumed constant.
Why ownership % changes monthly costs →
Disclaimer (2026): General information only; not financial, legal, or tax guidance.