Post-Purchase Upsell Revenue Calculator

What this calculator shows

This tool gives you a quick, honest estimate of the upside from a one-click post-purchase upsell. You put in four numbers, and it does the math instantly.

Here is the simple logic behind it. Out of all your monthly orders, some share of buyers will say yes to a follow-up offer. That share is the take rate. Multiply your orders by the take rate to get accepted offers. Multiply accepted offers by the offer price, and you have your extra monthly revenue. Times twelve gives you the yearly figure.

The "new AOV" line shows how a post-purchase offer nudges your average order value up. Even a modest take rate lifts the average, because every accepted offer stacks on top of an order that already happened.

Nothing here is a guarantee. It is a planning tool. The point is to see whether the math is worth your time before you set anything up.

What's a realistic take rate?

There is no single number that fits every store. Anyone who promises one is guessing.

What we can say honestly is this: a well-matched one-click offer that loads right after checkout often sees acceptance in the low-to-mid double digits. A weak or random offer can sit in the low single digits. The spread is wide on purpose.

Three things move the needle most:

• Relevance — does the offer fit what they just bought?
• Price — is it small next to the order they already placed?
• Timing — it shows after payment, while they still have buying momentum.

Our advice: start with a conservative guess in the calculator, like 8% to 12%. Launch, watch your real numbers for a couple of weeks, then come back and plug in what you actually see.

How to lift your take rate

The good news is the take rate is something you can improve. Small changes to the offer often move it a lot. Here is where to focus.

• Make the offer relevant. Pair it with what they just bought, like a refill, a case, or a matching item. See real post-purchase upsell examples for ideas that work.
• Keep it one tap. The whole point is no re-entered card and no second checkout. Friction kills the yes.
• Price it right against the order. An offer that feels small next to the order they just placed converts better. Learn how to write post-purchase upsell offers that land.
• Get the timing right. The offer should appear at the moment they are most ready to say yes. Read more on post-purchase upsell timing.

Why this revenue is basically "free" AOV

A post-purchase upsell is one of the cleanest ways to grow average order value, and here is why.

You already paid to win this customer. The ad spend, the email, the discount code — that cost is behind you. A post-purchase offer adds revenue on top of a sale you already made, with no new acquisition cost.

It is also one tap, and it shows only after the customer has paid. The original order is locked in first, so the offer cannot cost you the sale. The worst case is they skip it, and you are exactly where you started.

That is what makes it different from a discount or a pre-checkout upsell. There is no downside risk to the order. Want the full picture? Read about the one-click upsell after checkout.