A simple heuristic for the rent vs buy question — and why it works as a first filter even if the full calculator gives a more precise answer.
Multiply the home price by 5%. If your annual rent is less than that number, renting is likely the better financial choice. If your annual rent is more than that number, buying may make more sense.
Example: $500,000 home × 5% = $25,000/year. If your annual rent is under $25,000 ($2,083/month), renting is likely cheaper. If you're paying $3,000/month ($36,000/year), buying starts to look more attractive.
It represents the approximate annual unrecoverable costs of owning: roughly 3% for mortgage interest (cost of capital), 1% for property taxes, and 1% for maintenance. These are the costs you spend but don't recover — equivalent to "throwing money away" in the renting critique.
It ignores home appreciation, the investment return on the down payment if you rent, your local tax situation, and how long you'll stay (transaction costs of buying make short stays expensive regardless). Use it as a first filter, then use the full calculator for your actual numbers.