Calculate the ROI of influencer marketing before you sign. Enter influencer cost, reach, engagement rate and conversion assumptions to see cost per engagement, estimated revenue and whether the campaign stacks up.
Influencer marketing generates billions in brand investment but notoriously poor measurement. Most brands evaluate influencers on follower count and engagement rate — both easily gamed and only loosely correlated with purchase intent. The only metrics that ultimately matter are: how many people did the content reach who are genuinely likely to buy, and how many of those actually purchased. This calculator forces that quantification.
| Type | Followers | Typical Engagement | Typical CPE | Strength |
|---|---|---|---|---|
| Mega Influencer | 1M+ | 1–2% | £0.05–£0.50 | Reach & brand awareness |
| Macro Influencer | 100K–1M | 2–3% | £0.10–£1.00 | Reach + some trust |
| Micro Influencer | 10K–100K | 3–6% | £0.20–£2.00 | High trust, niche audience |
| Nano Influencer | 1K–10K | 5–10% | £0.30–£3.00 | Highest trust, very niche |
Micro-influencers (10K–100K followers) typically have higher engagement rates, more authentic audience relationships and charge significantly less per post. For product launches and direct response campaigns, 10 micro-influencers often outperform 1 macro-influencer at comparable total cost — with lower risk (if one underperforms, others compensate) and more niche targeting.
ROI = (Revenue from campaign - Influencer cost) / Influencer cost × 100. To measure revenue: use unique discount codes (10-15% of purchases typically use the code), custom UTM-tracked affiliate links, and post-purchase surveys asking "how did you hear about us?". Revenue attribution through influencer campaigns is genuinely difficult — many purchases happen later or through other channels after the influencer creates initial awareness.
General UK benchmarks: Nano (1K-10K followers) £50-500 per post; Micro (10K-100K) £200-2,000; Macro (100K-1M) £1,000-15,000; Mega (1M+) £10,000-100,000+. Rates vary enormously by niche, engagement rate, platform and content format. Instagram Stories are typically 50-70% of feed post rates. Negotiate: many influencers accept 70-80% of their quoted rate. Consider affiliate/commission structures for lower upfront cost with performance upside.
Cost Per Engagement (CPE) = Influencer Fee / Total Engagements (likes + comments + shares). A useful comparison metric across influencer tiers. Micro-influencers typically have lower CPE (£0.20-£2.00) than mega-influencers (£0.05-£0.50 per engagement sounds lower but reaches a less targeted audience). CPE should be used alongside engagement quality — comments and saves indicate higher intent than likes.