ARPU shows what an average paying customer is worth each month.

It matters because it tells you what each new customer adds.

ARPU links customer counts to revenue. Lifetime value and CAC payback both start from it, so it sets how much you can spend to win a customer.

It also shows where growth comes from. MRR can rise because you have more customers or because each one pays more, and ARPU separates the two.

Divide MRR by the number of paying customers.

ARPU = MRR ÷ paying customers

The average hides the mix of plans behind it.

In the example nobody pays $50. Most customers pay $30 and a few pay $180. ARPU moves whenever that mix moves, so track it for each plan as well as overall.

If 100 Starter customers move to Pro, each adds $50. MRR rises to $55,000 and ARPU to $55, with the same 1,000 customers.

ARPU and ARPA are the same sum on different units.

If you sell to individuals, one customer is one user, and ARPU is the natural name. If you sell to companies, one customer is an account with many users, and dividing by accounts gives ARPA. The formula does not change. What matters is that the bottom of the fraction is the thing that pays the invoice.

It is worth working out ARPU for new customers on their own as well. If customers who joined this quarter pay less than your overall average, the average will drift down as they become a larger share of the base.

You raise it by moving customers to plans that match how much they use.

• Price on something that grows with the customer. Seats, volume or usage let revenue rise as the account does.
• Make the next plan an easy step. Show the upgrade at the moment a customer reaches a limit, with the price and what they get.
• Give discounts an end date. A coupon that never expires pulls ARPU down for as long as the customer stays.
• Sell add-ons for the next problem. Revenue added from existing customers is expansion MRR, and it lifts ARPU directly.

These mistakes bend ARPU.

• Counting free users. Free-plan users and trials pay nothing. Divide by paying customers only, or say clearly that free users are included.
• Mixing users and accounts. One company with 20 seats is one account and 20 users. Pick one and name the metric to match.
• Using cash received in place of MRR. Annual payments and one-time fees landing in one month make that month's ARPU jump.
• Reading every rise as good news. ARPU also goes up when small customers leave. Check the customer count beside it.