Marketing calculators
Ten marketing calculators that show their working: CPM, CPC, CTR, conversion rate, ROI, LTV, CAC, A/B significance, ad budget and break-even, formulas shown.
- CPM calculatorWork out CPM from spend and impressions, or solve for either one instead. Shows the division it ran, and is precise that CPM prices a thousand impressions.
- Marketing ROI calculatorCalculate marketing ROI as a percentage, plus the net gain in money and the ROAS multiple, from one pair of figures. Explains why breaking even reads as 0%.
- Customer lifetime value calculatorCalculate customer lifetime value on gross margin or on revenue, plus the annual gross profit behind a payback period. Says which figure belongs next to CAC.
- CTR calculatorCalculate click-through rate from clicks and impressions, or solve for either one behind a rate. Explains which click column to use, since platforms differ.
- Conversion rate calculatorCalculate conversion rate from conversions and visitors, or work back to the traffic a target needs. Covers the sessions-or-users choice behind two answers.
- CPC calculatorWork out average cost per click from spend and clicks, or solve for the budget or the clicks instead. Explains why what you pay is rarely the bid you set.
- Customer acquisition cost calculatorCalculate customer acquisition cost three ways at once: media only, fully loaded with salaries and tools, and blended. Says which costs each one includes.
- A/B test significance calculatorCalculate relative lift, absolute lift and two-tailed significance for an A/B test from four numbers, with a warning when the sample is too small to hold.
- Ad budget calculatorWork backwards from a conversion target to the total budget, the daily cap and the cost per conversion, from your own click price and landing page rate.
- Break-even calculatorFind break-even units and revenue from fixed costs, price and variable cost, plus the contribution margin and the ROAS an ad campaign has to clear first.
Which calculator you need
All ten run in your browser, show the sum they performed, and are precise about the definition they used. Pick by the question you are being asked rather than by the acronym somebody used, because several of these terms mean different things to different people in the same meeting.
- CPM calculator: reach for this when you are buying or selling exposure and need the price of a thousand impressions, or the budget or impression volume behind a known rate.
- Marketing ROI calculator: use this when somebody has asked whether the activity paid, and you need the percentage, the money and the ROAS multiple to be consistent with each other.
- Customer lifetime value calculator: use this before setting any acquisition budget, because it sets the ceiling on what you can afford to pay for a customer.
- CTR calculator: use this to diagnose whether creative and targeting agree, or to size the impressions behind a click target.
- Conversion rate calculator: use this when the argument is about the denominator, or when you need to know what traffic a conversion target implies.
- CPC calculator: use this when the auction is charging you something different from what you bid, and you need the real price of a click.
- Customer acquisition cost calculator: use this when the definition is the argument, since it computes the media-only, fully loaded and blended versions side by side.
- A/B test significance calculator: use this when you have a result and need to know whether it is evidence, including an explicit warning when the sample is too small.
- Ad budget calculator: use this at the planning stage, to turn a conversion target into a total budget and a daily cap before money moves.
- Break-even calculator: use this to find the volume that covers your fixed costs, and the return on ad spend advertising must beat to contribute anything.
The definitions these pages refuse to fudge
Marketing arithmetic is easy and marketing definitions are contested, so almost every wrong answer in this area comes from two people computing different quantities and comparing them anyway. These are the four places the disagreement does the most damage, and where each page states its position rather than leaving it implied.
- CPM is priced per thousand impressions, not per thousand people. A viewer served the same ad four times generates four impressions and is billed four times, so cost per thousand reached is a separate and always larger figure.
- Acquisition cost changes by roughly a factor of two depending on whether salaries, retainers and production are loaded into it, and again depending on whether organic customers sit in the denominator. The CAC page computes all three versions at once so the spread is visible on your own numbers.
- Lifetime value on revenue and lifetime value on gross margin differ by exactly your margin. Only the margin version can be compared against an acquisition cost, and the revenue version is the one most published examples quietly use.
- Return on investment is computed on gain and return on ad spend is computed on revenue, so break-even reads 0% in one and 1.00 in the other. Both are correct and they are not the same claim.
- A significance figure describes how surprising your data would be if the two versions were identical. It is not the probability that the variant is better, and it says nothing about whether the difference is large enough to be worth shipping.
These numbers only mean something together
Any single metric here can be improved by making the business worse, which is why an account judged on one of them tends to drift somewhere unhelpful. The chain below is the order the figures constrain each other, and each link is a page in this family.
- Contribution margin sets the break-even return on ad spend, which is the floor every campaign has to clear before it contributes anything.
- Lifetime gross profit sets the ceiling on acquisition cost. Paying above it buys growth funded from somewhere else, which is a decision rather than an accident.
- Click price and conversion rate multiply into cost per conversion, which is the figure that decides whether a channel is viable at all.
- Click-through rate and cost per thousand impressions between them determine the click price, which is why creative quality shows up in the budget rather than only in the engagement report.
- A/B testing moves conversion rate, which relaxes every constraint above it at once. That is why testing pays even when individual tests do not reach significance.
What none of these can do
These are arithmetic tools operating on figures you supply, which means they inherit every problem in the measurement underneath. Being clear about the boundary is more useful than adding another decimal place to the output.
- They cannot tell you what your advertising caused. Attributed revenue includes purchases that would have happened anyway, and only a holdout or a matched-market test separates the two.
- They cannot reconcile your ad platform with your analytics. Those tools use different attribution windows and different denominators, and the gap between them is structural rather than a bug to be fixed.
- They cannot repair a badly defined conversion event. If the underlying tag double counts or misses consent-declined visitors, every rate computed from it inherits the error.
- They cannot supply a benchmark worth using. Published averages span industries with wildly different margins and intent, and your own figure from last quarter is a far better comparison.
- Nothing entered on any of these pages is transmitted anywhere. The arithmetic runs in your browser, so campaign data, revenue and margins stay on your machine.
The rest of the job
You just fixed one post. Now do the month.
The marketing calculators solves one piece of one post. OctoSpark plans, writes and schedules the whole calendar across every network you use, publishes it for you, and reports what actually performed.
- One calendar for every network
- Schedule once, publish everywhere
- Drafts written in your own voice
- See what actually performed
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Frequently asked questions
How this tool works, what it cannot do, and what happens to what you put into it.
Are these calculators free, and is my data sent anywhere?
They are free and nothing leaves your browser. Every page in this family is plain arithmetic executed on your device, with no account, no upload and no server call, which is why they work offline once the page has loaded. That matters here more than on most tools, because the inputs are spend, revenue and margin figures that many people are not permitted to paste into a third-party service.Which of these should I calculate first?
Start with break-even, because contribution margin sets the threshold every other number is judged against. Then lifetime value on gross margin, which caps what you can pay to acquire a customer. With those two in hand, the acquisition cost, ad budget and return calculations stop being abstract comparisons and become decisions with a pass mark attached.Why do these show more than one answer for the same metric?
Because the metrics genuinely have more than one accepted definition, and hiding that would make the tools less useful rather than simpler. Acquisition cost is quoted three ways in ordinary business use, lifetime value two ways, and returns as both a percentage and a multiple. Showing them together makes the spread visible on your own figures, which is usually more persuasive than an argument about which definition is proper.Can I use these for a client report?
Yes, and the thing to carry across with the number is the definition. Each page prints the exact sum it ran, so quoting that line alongside the result makes the figure reproducible by whoever receives it. A marketing number without its formula attached invites a challenge that nobody can settle, which is how a correct calculation ends up being overruled by a wrong one.Is my data private?
Yes. This tool does its work in your browser, so whatever you type, paste or upload stays on your device. Nothing is sent to our servers, which is also why it keeps working if you go offline after the page has loaded.Is this really free?
Yes. Every tool here is free with no account, no credit card and no usage cap. They exist so that the people who need our scheduling product find us, which only works if the tools are genuinely useful on their own.Do I need an account?
No. Open the page and use it. An account is only for OctoSpark itself, where you plan, schedule and publish a whole calendar rather than fixing one post at a time.Can I use the output commercially?
Yes. Anything you produce here is yours, including for client and commercial work. We claim no rights over it and we do not watermark it.