◆ Free tools

Direct mail tools & calculators

Two quick calculators to help you think through a targeted mailing before you commit to anything: what a model might be worth for your numbers, and how big a test you’d need to trust the result.

What a model is worth, in dollars

Plug in your own numbers to see the potential payoff of targeting who you mail, versus mailing everyone. This uses the decile-based pattern from a worked example with realistic but illustrative data ↗ — not an actual client engagement — rescaled to whatever inputs you enter.

Try it with your own numbers

Rough estimate only. Phase 0 confirms the real numbers for your list.

Households mailed per campaign

Mailings planned per year

Average response / sales rate among mailed (%)

Average value per response or sale ($)

Average cost per piece mailed ($)

Have you tested a holdout (a similar group you deliberately didn’t mail)?

Ready to talk specifics? Book a free scoping call ↗

How big a test do you need?

If you’re planning to hold out a group to measure a model’s real impact, the holdout needs to be big enough that a real difference shows up as a real difference — not noise. This calculator tells you the minimum group size needed to reliably detect the difference you care about.

How big a sample do I need?

Two-tailed test, 95% confidence, 80% power — the standard, conservative default.

Baseline response rate (%)

Minimum difference you want to detect (percentage points)

Not sure your holdout is big enough? Book a free call and we’ll check ↗