CPA Bid Calculator
Turn a target CPA into the bid you can actually place. Enter your target CPA and conversion rate and this calculator returns the maximum CPC and maximum CPM you can pay, checks them against our published floors, and shows how fast the bid collapses if your conversion rate slips.
Bidding backwards from a target CPA
A bid is not a negotiation, it is arithmetic. If you will pay $25 for a conversion and 2% of your clicks convert, then one conversion costs 50 clicks, so a click is worth $0.50 to you. Bid a cent more and the campaign loses money at the rate you scale it.
The same logic converts a CPC into a CPM. At a 0.8% CTR, a thousand impressions produce eight clicks, so a $0.50 maximum CPC is a $4.00 maximum CPM. That conversion is how you compare a push campaign priced per click against pop inventory priced per thousand impressions without guessing.
The number to look at hardest is the sensitivity table. Conversion rate is measured on a sample and it moves - a new creative, a weekend, a different sub-source. If halving your conversion rate takes the supportable bid below what traffic actually costs in your GEO, the campaign is not merely tight, it has no room to be wrong. Buy a small test first, measure the real rate, then set the bid.
The max bid formula
- Max CPC = target CPA x conversion rate
- Max CPM = max CPC x CTR x 1,000
- Conversion rate = max CPC / target CPA
- Clicks per conversion = 1 / conversion rate
CPA bid calculator FAQ
- How do I convert a target CPA into a CPC bid?
- Multiply your target CPA by your conversion rate. A $25 target CPA at a 2% conversion rate supports a $0.50 maximum CPC, because it takes 50 clicks to make one conversion.
- How do I convert a CPC bid into a CPM bid?
- Multiply the CPC by your CTR and by 1,000. At a 0.8% CTR a $0.50 CPC is a $4.00 CPM, because a thousand impressions produce eight clicks.
- What if my max CPC is below the network floor?
- Then the target is not biddable on that format. TrafficSigma push inventory starts at a $0.005 CPC and native at $0.002. If your maximum sits under the relevant floor you need a higher payout, a better conversion rate, or a cheaper GEO.
- Should I bid my maximum?
- No. The maximum is your break-even, not your target. Bid below it so the gap becomes your margin, and use the sensitivity table to decide how big that gap needs to be.
- How much can my conversion rate move?
- On a fresh campaign, a lot - early conversion rates are measured on small samples. The table above shows your supportable bid at half and one and a half times the rate you entered precisely because that range is normal, not exceptional.
- Does a target CPA campaign do this for me?
- An automated target CPA mode bids on your behalf, but it still needs a realistic target and enough conversion data to learn from. Working the bid out by hand first tells you whether the target you are about to set is achievable at all.