A field guide from PocketLedger
Keep the cash flows separate
A projected total can hide several different stories. In a loan, principal is the amount borrowed and interest is the cost of financing it. In a savings model, contributions are the money you add and growth is the change produced by the selected rate. Look at those pieces separately before comparing two totals. PocketLedger exposes these components so changing the term or deposit amount has a visible consequence.
Make the period match the rate
Our loan and compound-growth models use monthly periods. The annual percentage entered is divided by twelve for each monthly period. That nominal-rate convention is different from entering an effective annual return. When comparing a result to a bank illustration, confirm which convention it uses, whether payments occur at the start or end of a period, and whether the quote includes fees.
Use more than one scenario
A calculator is useful for asking a controlled question. Change one field at a time: increase a monthly contribution, shorten a loan term, or choose a lower assumed growth rate. Save the inputs with the result so you can reproduce the comparison. A longer term may lower a loan payment while increasing total interest; a higher modeled return changes a projection but does not make it more certain.
Check costs outside the model
Taxes, inflation, account fees, insurance, penalties, and irregular payments can change real outcomes. The tools do not collect your financial circumstances and do not recommend products. For a purchase discount, the tax field applies to the discounted price, which may not match every local checkout rule. Treat the result as an arithmetic estimate and compare it with the actual contract or receipt before relying on it.