Both have free money calculators, and they answer different questions. NerdWallet's calculators project forward from growth rates you set. Ctrl Alt Decide replays what really happened at a real place and date.
| NerdWallet | Ctrl Alt Decide | |
|---|---|---|
| What it answers | What might happen: it projects forward from rates you enter or accept. | How a choice turned out: it replays what really happened at a real place and date. |
| Where the numbers come from | Growth rates set by you or by NerdWallet's defaults, such as "Home appreciation (yearly)", "Rent increase (yearly)" and "Annual rate of return". | Published records for your place and month: HM Land Registry, ONS, Zillow, Freddie Mac, Bank of England and more. You can type over any figure. |
| Rent or buy | Yes, projected forward from the rates above. US only. | Yes, for over 600 UK and US places, back to 2015. |
| Overpay the mortgage or invest | An early payoff calculator that finds the extra payment needed. No invest-instead comparison. | Yes: overpaying against investing, back to 2000. |
| Lease or buy a car | A lease payment calculator. It doesn't compare leasing with buying. | Yes: leasing, a car loan or paying cash, compared. |
| Savings or investing | Compound interest and savings calculators, with a return rate you estimate. | Cash savings against the stock market, with real savings rates and returns back to 2000. |
| Moving city | A cost of living comparison for US cities, using today's prices. | Pay, rents and house prices in two places, replayed since 2015. |
| Pay against inflation | An inflation calculator that converts a dollar amount between dates with the US consumer price index. No pay comparison. US only. | Yes: your pay then and now against prices and real average pay, UK and US, back to 2000. |
| Stock markets by country | An investment calculator that grows money at a rate of return you type in. No real past returns and no other countries. | Yes: two countries' real share prices side by side, in pounds or dollars, back to 2000. |
| UK coverage | US only. NerdWallet's UK site closed in 2026. | UK and US. |
| Account needed | Not needed. | Not needed. |
| How it makes money | Some financial companies whose products appear on the site pay NerdWallet, for example referral fees. | No ads, no affiliate links, no paid version. |
You're planning ahead and want editor-set national defaults, today's cost of living in US cities, or links to shop for current rates. It also covers far more topics.
You want to know how a choice actually played out: in your place, from the month you made it, with the real prices, rents and rates since. It covers the UK as well as the US, and every figure names its source.
Checked on 23 September 2026 against NerdWallet's own pages: NerdWallet rent vs buy calculator, How NerdWallet makes money. Spotted something out of date? Tell us at @ctrlaltdecide.