# Cost Per Install (CPI) Calculator Calculate cost per install and break down the full funnel from impressions through installs to Day-30 retained users. --- - **Canonical URL:** https://dothecalculation.com/calculators/cost-per-install-calculator - **Category:** Creative & Digital Marketing - **Publisher:** Do The Calculation (https://dothecalculation.com) - **Cost:** Free, no account or sign-up required - **Privacy:** Runs entirely in the browser; inputs are never sent to a server - **Methodology:** https://dothecalculation.com/methodology --- ## Break down your Cost Per Install across the full funnel Go beyond spend ÷ installs — see CTR, CPC, click-to-install rate, and cost per retained user in one place. - Full funnel: impressions → clicks → installs - Cost per Day-30 retained user - Spot where the funnel is actually leaking ## CPI is one number that hides three different problems Cost Per Install (CPI) is simply total ad spend divided by the number of installs it produced: CPI = Spend ÷ Installs. That single number is useful for budgeting, but it collapses three very different funnel stages into one figure — how many people saw the ad (impressions), how many of those clicked (CTR), and how many of those clicks converted to an actual install (click-to-install rate, sometimes called store-page conversion rate). Two campaigns can land on the exact same CPI for completely different reasons: one with a weak ad but a strong app store listing, another with a strong ad but a confusing store listing — and only breaking down the funnel reveals which lever to pull. ## Where CPI actually goes wrong: a worked comparison Campaign A: $1,000 spend, 200,000 impressions, 2,000 clicks (1% CTR), 100 installs (5% click-to-install rate) → CPI = $10. Campaign B: $1,000 spend, 50,000 impressions, 2,000 clicks (4% CTR), 100 installs (5% click-to-install rate) → also CPI = $10. Both campaigns land on identical $10 CPI, but Campaign A's ad creative is underperforming relative to its audience (1% CTR is low), while Campaign B's ad is working well (4% CTR) — the bottleneck in Campaign B is elsewhere, or the audience is simply smaller. Without the funnel breakdown, both would get the same 'fix the CPI' diagnosis, when they need opposite fixes. ## CPI measures acquisition, not value — that's the real limitation Global average CPI runs around $0.53 for Android and $1.24 for iOS, per AppsFlyer's benchmark data, but a low CPI is not automatically a good outcome. CPI counts every install equally, whether that user opens the app once and deletes it or becomes a paying long-term customer. This is why performance marketers pair CPI with a Day-30 (or Day-7) retention check and a cost-per-retained-user figure — a campaign with a higher CPI but meaningfully higher retention can be the better spend even though the headline number looks worse. ## Reading the retention-adjusted numbers Cost per Retained User = Spend ÷ (Installs that are still active after your retention window, e.g. Day 30). If 100 installs cost $1,000 (CPI = $10) but only 40 of them are still active 30 days later, the real cost per retained user is $1,000 ÷ 40 = $25 — two and a half times the headline CPI. That $25 figure is what actually belongs next to Customer Lifetime Value (LTV) when deciding whether a channel is profitable, not the raw CPI. ## Related calculators Working the mobile-store side of this funnel? The [ASO & Conversion Calculator](/calculators/aso-conversion-calculator) breaks down store-listing conversion specifically. Comparing this channel's efficiency against paid acquisition elsewhere? See the [Marketing CPA Calculator](/calculators/marketing-cpa-calculator) for cost-per-acquisition on non-install conversion events, and the [Ad Revenue Calculator](/calculators/ad-revenue-calculator) if the app itself is ad-monetized and you need to weigh acquisition cost against in-app ad revenue. ## Frequently asked questions ### What is the Cost Per Install (CPI) formula? CPI = Total Ad Spend ÷ Number of Installs. If $1,000 in spend produces 200 installs, CPI is $5. ### What's a good CPI for a mobile app? It varies widely by category and platform, but global averages run around $0.53 for Android and $1.24 for iOS according to AppsFlyer benchmark data. Gaming and finance apps often run higher; utility apps often run lower. ### Why do two campaigns with the same CPI perform differently? Because CPI collapses CTR (ad quality) and click-to-install rate (store listing quality) into one number. Two campaigns can reach the same CPI through very different funnel strengths, which only shows up when you break the funnel apart. ### Is a lower CPI always better? Not necessarily. CPI measures acquisition cost, not user quality. A cheaper install that churns immediately can cost more per retained or paying user than a pricier install that sticks around — check retention alongside CPI. ### What's the difference between CPI and CAC? CPI (Cost Per Install) counts every install, including users who never engage further. CAC (Customer Acquisition Cost) typically counts only users who reach a meaningful action, like a purchase or subscription — CAC is usually higher than CPI for the same campaign. ### How is click-to-install rate different from CTR? CTR measures ad clicks ÷ ad impressions (did the ad get clicked). Click-to-install rate measures installs ÷ clicks (did the click actually convert once someone reached the app store listing) — a weak store listing shows up here even when CTR looks fine. ### Should I optimize for CPI or cost per retained user? Cost per retained user is the more decision-useful number for budget allocation, since it reflects users still active after your retention window, not just users who briefly installed. CPI remains useful for quick campaign-level budgeting and comparisons within the same channel. ## Related concepts - **CPI (Cost Per Install)** — Total ad spend divided by number of installs — the standard mobile acquisition cost metric. - **Click-to-install rate** — The percentage of ad clicks that convert into an actual app install, isolating store-listing performance from ad performance. - **Cost per retained user** — Spend divided by the number of installs still active after a defined window (commonly Day 30) — a better proxy for acquisition efficiency than raw CPI. ## Related guides - [Paid Media Metrics Guide: CPC, CPM, CTR, CPA, ROAS, and ROI in Plain English](https://dothecalculation.com/blog/marketing/paid-media-metrics-guide) — Understand the paid media metrics that actually matter. Learn how CPC, CPM, CTR, CPA, ROAS, and ROI connect, when to use each one, and how to avoid reporting cheap traffic as business success. - [Understanding Calculator Formulas: How DTC Turns Inputs into Results](https://dothecalculation.com/blog/site-guides/understanding-calculator-formulas) — Understand how Do The Calculation formulas are presented, what the explanation blocks mean, and how to verify calculator logic before using a result in a real decision. ## Related calculators - [CPM Calculator](https://dothecalculation.com/calculators/cpm-calculator) — Estimate cost per thousand impressions, click-through rate, and blended media efficiency to plan and optimize your ad campaign budget. - [Ad Click-Through Rate (CTR) & CPC Calculator](https://dothecalculation.com/calculators/ad-ctr-cpc-calculator) — Calculate click-through rate, cost per click, and cost per mille for your ad campaigns to evaluate paid advertising performance. - [Ad Frequency & Fatigue Estimator](https://dothecalculation.com/calculators/ad-frequency-fatigue-calculator) — Model ad fatigue over time based on reach, impressions, and click-through rate parameters to know when to refresh creative assets. - [Break-Even ROAS Calculator](https://dothecalculation.com/calculators/breakeven-roas-calculator) — Determine the minimum return on ad spend needed to cover product cost and achieve profitability for your paid advertising campaigns. - [Click-Through Rate (CTR) Calculator](https://dothecalculation.com/calculators/ctr-click-through-rate-calculator) — Calculate click-through rate from impressions and clicks, with benchmark comparisons, to measure ad or email campaign engagement. - [SMS Marketing Conversion Rate & CTR Calculator](https://dothecalculation.com/calculators/sms-marketing-conversion-calculator) — Calculate click-through rate, opt-out rate, conversion rate, cost per conversion, and ROI for your SMS text marketing campaigns. --- _Benchmark CPI figures cited here (Android ~$0.53, iOS ~$1.24) come from AppsFlyer's published mobile marketing benchmark data and represent broad averages — actual costs vary significantly by app category, region, and season._ --- _Source: [Do The Calculation](https://dothecalculation.com/calculators/cost-per-install-calculator). Quote freely with attribution and a link to this page._