Why per-square-foot is the honest comparison
Listings quote monthly rent, but monthly rent tells you almost nothing across different units: a $2,400 apartment and a $1,900 apartment cannot be compared until you know what each buys. Per-square-foot pricing is the normalization that makes listings comparable — monthly rent ÷ square footage — and this calculator runs it both ways: the monthly rate (/sq ft/month) and the annual rate (× 12, quoted/sq ft/year, the convention commercial leasing uses).
The defaults illustrate why the extra division matters: a $2,400 unit at 750 sq ft costs $3.20 per square foot monthly; a $1,900 unit at 800 sq ft costs $2.38. The cheaper-looking apartment is 34% more expensive per foot of living space. That gap is where the real decisions live — the $1,900 unit at the $3.20 rate would be a 600-square-foot apartment; whether you are paying for location, building amenities, or just poor math determines which listing is actually the deal.
Two consistency rules when comparing: count usable square footage the same way for every listing (some landlords quote gross building area including walls and shared space; others quote carpet area), and decide whether utilities are inside or outside the rent before trusting the number — a $2.38 rate with tenants paying electric and water can exceed a $2.60 rate with everything included. The calculator prices the rent line; the utility check is a one-line addition on your comparison sheet.