Ad spend scaling simulator
Compare 1.5×, 2× and 3× budgets under your explicit CPA-increase assumption.
Last updated
Linear assumed scenarios — not a forecast
- 1× budget: spend
- £1,000.00
- Hypothetical budget for the same period.
- 1× budget: CPA
- £25.00
- Derived from your linear CPA-increase assumption, not a forecast.
- 1× budget: expected orders
- 40
- Fractional values are an expectation.
- 1× budget: contribution after ads
- £600.00
- Before fixed overhead. Negative values mean a contribution loss.
- 1.5× budget: spend
- £1,500.00
- Hypothetical budget for the same period.
- 1.5× budget: CPA
- £27.50
- Derived from your linear CPA-increase assumption, not a forecast.
- 1.5× budget: expected orders
- 54.55
- Fractional values are an expectation.
- 1.5× budget: contribution after ads
- £681.82
- Before fixed overhead. Negative values mean a contribution loss.
- 2× budget: spend
- £2,000.00
- Hypothetical budget for the same period.
- 2× budget: CPA
- £30.00
- Derived from your linear CPA-increase assumption, not a forecast.
- 2× budget: expected orders
- 66.67
- Fractional values are an expectation.
- 2× budget: contribution after ads
- £666.67
- Before fixed overhead. Negative values mean a contribution loss.
- 3× budget: spend
- £3,000.00
- Hypothetical budget for the same period.
- 3× budget: CPA
- £35.00
- Derived from your linear CPA-increase assumption, not a forecast.
- 3× budget: expected orders
- 85.71
- Fractional values are an expectation.
- 3× budget: contribution after ads
- £428.57
- Before fixed overhead. Negative values mean a contribution loss.
How to use this tool
Use one reporting window and a consistent measurement scope. Replace the example inputs with your own figures. The result updates locally as you type. Copy the result to your planning notes, or copy a link containing only the numeric inputs. Reset restores the illustrative example.
- Enter current spend and CPA.
- Choose a stated assumption for how CPA changes as spend rises.
- Read projected CPA and profit at 1.5x, 2x and 3x spend.
- Compare against your max CPA to see where scaling stops paying.
Worked example
At £1,000 spend and £25 CPA, the baseline is 40 orders. With a 20% CPA increase for each additional baseline budget, 1.5× spend implies £27.50 CPA, 2× implies £30 and 3× implies £35. These are assumptions, not predictions from account data.
Formula and units
Scenario CPA = baseline CPA × [1 + assumed CPA increase × (spend multiplier - 1)]. Expected orders = scenario spend / scenario CPA. Contribution after ads = expected orders × contribution/order - spend.
Assumptions and review notes
The model is linear in CPA deterioration, not an auction forecast. Fractional orders represent an expectation, not a fulfilment count. It excludes inventory, cash timing, audience overlap, conversion lag and learning effects. Use it to see how sensitive the plan is to a worse CPA, then make actual decisions from measured performance and cash constraints.
The simulator shows what happens under an assumption you state. It is not a forecast, and real accounts vary widely, so scale in steps and measure.
- Audience size.
- Creative fatigue.
- Auction competition.
- Platform learning.
- Treating the assumption as a prediction.
- Scaling in one jump.
- Ignoring frequency.
- Using a CPA from a tiny sample.
A closer look
Common questions.
- Is this a forecast?
- No, it illustrates an assumption you choose.
- What assumption should I use?
- Use your own history where you have it.
- How fast should I scale?
- Gradually, checking results at each step.
- Why does CPA rise at scale?
- Larger spend reaches less responsive people.
- Does it store data?
- No.