Facebook Ads Budget Calculator
Estimate your monthly Facebook Ads budget based on conversion goals, cost-per-click, and conversion rate. Use it when planning a new campaign or scaling an existing one to avoid overspending.
About this calculator
This calculator determines how much you need to spend on Facebook Ads to hit a specific number of monthly conversions. The core logic works backward from your goal: if you want 200 conversions and your landing page converts 4% of visitors, you need 5,000 clicks. Multiply those clicks by your cost-per-click to get the raw budget. Finally, a buffer percentage is added to account for auction volatility and unexpected costs. The full formula is: Budget = (targetConversions / (conversionRate / 100)) × CPC × (1 + buffer / 100). For example, a 20% buffer adds a safety margin so your campaign doesn't stall mid-month. Knowing your industry benchmark CPC and realistic conversion rate are the two most important inputs for accuracy.
How to use
Suppose you want 100 conversions per month. Your landing page converts at 5%, your average CPC is $1.50, and you want a 20% buffer. Step 1 — Calculate clicks needed: 100 / (5/100) = 2,000 clicks. Step 2 — Raw budget: 2,000 × $1.50 = $3,000. Step 3 — Add buffer: $3,000 × (1 + 20/100) = $3,000 × 1.20 = $3,600. Your recommended monthly Facebook Ads budget is $3,600.
Frequently asked questions
How do I find my Facebook Ads cost per click before running a campaign?
Before launching, you can estimate your CPC using Facebook's Ads Manager audience insights or industry benchmark reports. Average CPCs vary widely by industry — retail often sees $0.70–$1.50, while finance can exceed $3.00. Tools like WordStream and HubSpot publish annual Facebook CPC benchmarks by sector. Start with the industry average and refine after your first week of live data.
What is a good landing page conversion rate to use in the Facebook Ads budget calculator?
A typical landing page conversion rate across industries is 2–5%, but high-performing pages can reach 10–15%. For conservative budget planning, use 2–3% if your page is new or untested. If you have historical data from Google Analytics or your CRM, use your actual rate for the most accurate budget estimate. A higher conversion rate means you need fewer clicks — and a lower budget — to hit your conversion goal.
Why should I add a budget buffer to my Facebook Ads spend estimate?
Facebook's ad auction is dynamic — CPCs can spike during high-competition periods like holidays, product launches, or news events. A buffer of 10–20% ensures your campaign keeps running even if costs temporarily rise. Without a buffer, your campaign may exhaust its budget before the month ends, causing gaps in delivery and lost conversions. Think of the buffer as insurance against forecast uncertainty rather than wasted spend.