FundamentalsHow compound interest actually works
Why money that earns money is the quiet engine behind every long-term plan — and the maths you can do on a napkin.
7 min read
Independent · Fiduciary · No hype
Money decisions, made legible.
Northpeak turns personal finance into plain English. Honest explainers and calculators that show their assumptions — so you can decide for yourself, not be sold to.
The long view
Wealth is built slowly, with clear eyes and stated assumptions.
Fiduciary by default
We write what serves you, not a product we're paid to push.
Assumptions stated
Every projection lists the rate, horizon, and what it ignores.
Plain English
No jargon walls. If a term matters, we define it in context.
No get-rich claims
Just durable fundamentals — compounding, costs, and patience.
01 / Learn
Start with the fundamentals
Fundamentals
02 / Calculate
Honest calculators, no sign-up
Move a slider, see the maths update live. Each tool states its assumptions and reminds you that estimates aren't guarantees.
Open the calculatorsCompound Interest
See how a starting balance plus regular contributions can grow over time at an assumed annual return.
Mortgage Payment
Estimate the monthly principal-and-interest payment on a fixed-rate mortgage, plus total interest paid.
Savings Goal
Work out the monthly amount needed to reach a savings target by a chosen date, with optional interest.
Read the methodology behind every word.
Who writes Northpeak, how we choose topics, and our editorial standards — all on the record.