Tallyday Guides
A little context makes a calculation more useful.
Short, practical reading for the assumptions behind common everyday numbers. Each guide leads directly to a free tool when you are ready to try your own inputs.
Home finance guide
How to calculate a mortgage payment: the numbers to check
Understand the inputs behind a principal-and-interest mortgage payment estimate and the costs to plan for separately.
4 min read Read guide →
Health basics guide
BMI: what the number can and cannot tell you
Learn what body mass index measures, how the calculation works, and why one number cannot describe a person’s health on its own.
3 min read Read guide →
Personal finance guide
How much should you save each month for a goal?
Turn a savings target and deadline into a monthly contribution estimate, then pressure-test the plan against real life.
4 min read Read guide →
Work pay guide
How to calculate overtime pay without missing the assumptions
Estimate gross overtime pay from hours, an hourly rate, and a multiplier while keeping local wage rules and employer policies in view.
3 min read Read guide →
Everyday money guide
How to split a bill fairly and quickly
Use a simple per-person estimate for an even split, then decide what to do when people ordered different amounts.
3 min read Read guide →