How much should a UK small business spend on ads?

'How much should I spend on ads?' is the question every UK founder asks, and the answer nobody gives them is: it depends on your revenue, your margins, and your stage. Here's a practical framework.

The percentage-of-revenue rule

A common benchmark is 7–12% of gross revenue for established businesses, and 15–25% for early-stage companies seeking growth. If you're a UK e-commerce brand doing £10k/month, that's £700–£1,200/month for an established business, or £1,500–£2,500/month if you're aggressively scaling.

The unit economics approach

Forget percentages — work backwards from your numbers. If your average customer is worth £200 (LTV), and you want a 3x return on your ad spend, your maximum cost per acquisition (CPA) is £66. If your platform CPCs average £1.50 and your conversion rate is 3%, your CPA is £50. You're profitable — and you should scale. If the maths doesn't work, fix the conversion rate or the creative before increasing budget.

Budget allocation by channel

For most UK SMEs, a sensible starting split is: 50% on Google Search (high intent, reliable), 30% on Meta (awareness and retargeting), 10–15% on TikTok (if your audience is under 35), and 5–10% reserved for testing new channels. Adjust monthly based on which platform delivers the lowest CPA.

When to increase your budget

Scale when your CPA is consistently below your target for 2+ weeks. Increase by 20% at a time — not doubling overnight. Watch CPA and ROAS closely for the first 5–7 days after each increase; performance often dips briefly as the algorithm re-learns, then stabilises. If CPA stays elevated after a week, scale back.

The one number that ties it together

Every budget decision comes down to ROAS vs margin. If you can't see ROAS across all your platforms in one place, you're guessing. AdPulse auto-calculates ROAS per platform and shows whether scaling makes sense. Start free.