Blog

Long-form guides that explain the math behind our calculators. Written and reviewed by Larius and the Handy Calculators editorial team.

• Real Estate · 8 min read

  How to calculate cap rate for a rental property

  Capitalization rate, line by line. We walk through NOI, gross vs net cap rate, what counts as a good cap rate by market, and the three mistakes that quietly inflate every novice calculation.

• Health · 7 min read

  BMI vs body fat percentage — which actually matters?

  BMI is everywhere but it isn't measuring what most people think. We compare BMI, body fat percentage, waist-to-height, and body roundness, and explain when each one is the right tool.

• Money · 9 min read

  Refinance break-even, explained step by step

  How to decide whether refinancing your mortgage is actually worth it. Closing-cost recovery, the amortization reset trap, and break-even math walked through with two real examples.

• Health · 7 min read

  Macro split for fat loss vs muscle gain

  Protein, carbs, and fat targets for a cut, a maintenance phase, and a lean bulk — with the calorie math, the protein floor, and how to set fat as a minimum rather than a residual.

• Money · 6 min read

  Understanding APR vs APY (with worked examples)

  APR and APY look interchangeable on a marketing page and aren't. We walk through the compounding math, when each one applies, and how to convert between them without getting fooled by the disclosure.