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Guide

Cost of Living Basics

By Shahid Saleem • February 28, 2026

A human guide to what cost-of-living indices actually mean and how to use them in real life.

Cost of Living Basics

Cost-of-living numbers can feel abstract until you put them next to your actual budget.
This guide walks through how the indices on RentX work and how to read them without overthinking it.

In this guide

  • What a cost-of-living index is
  • How to read category scores (rent, groceries, etc.)
  • Ways to use these numbers with your own budget
  • Common mistakes to avoid
  • FAQs

What a cost-of-living index actually measures

A cost-of-living index is a comparison tool, not a bill.
On RentX, we treat 100 as the estimated US average across major categories:

  • Above 100: likely more expensive than average.
  • Below 100: likely less expensive than average.

The big idea: an overall index of 120 suggests that everyday spending might be roughly 20% higher than the US average. It's not perfect, but it's a fast way to compare two places using the same yardstick.

Category scores: rent, home price, groceries and more

Every city page breaks the index into categories so you can see where the differences come from.

  • Rent index – a rough sense of what typical rents look like.
  • Home price index – how purchase prices compare, in broad strokes.
  • Utilities – electricity, gas, water, basic internet.
  • Groceries – everyday food and household items.
  • Transportation – gas, transit passes, basic car costs.
  • Healthcare – routine care and common insurance assumptions.

Two cities might share a similar overall index but feel very different in practice because, for example, rent is high but groceries are cheap in one, and the opposite is true in another.

Using indices with your own budget

Numbers are only useful when they connect back to your life. A simple approach:

  1. List your current monthly spending in big buckets (housing, groceries, transport, etc.).
  2. Look up the city you're considering on RentX.
  3. Compare each category's index to 100 and ask, “What happens if this line item goes up (or down) by that much?”

You don't have to rebuild your entire budget. Even a back-of-the-envelope comparison can show whether a move looks roughly sustainable or likely to be a stretch.

Common mistakes to avoid

Some quick pitfalls to watch out for:

  • Treating the index as a quote – it's not. It's an estimate for comparison.
  • Ignoring your own lifestyle – if you don't own a car, transportation indices mean something different to you than to a daily commuter.
  • Overlooking taxes and benefits – local tax rules and employer benefits can outweigh a higher grocery bill.
  • Assuming every neighborhood matches the index – within a city, costs can vary a lot block by block.

FAQs

Is the index guaranteed to match what I'll pay?

No. Real-world prices change constantly, and your situation is unique. Treat the index as a starting point, not a promise.

How do I check whether the numbers feel realistic?

Compare the indices with current rental listings, home listings, local transit prices, and your own quotes. If something feels off, trust the real, local data first.

Can I use the index when negotiating a salary?

Yes, as one of several inputs. Many people use cost-of-living comparisons to frame conversations about remote work pay, relocation packages, or raises after moving to a more expensive area.

Where should I go next?

Helpful links