Free Marketing Calculators: Advertising ROI, CAC, Conversion Rate & Email Revenue (2026)

Quick answer: Advertising ROI = (revenue from ads − cost of goods − ad spend) ÷ ad spend × 100. Customer acquisition cost (CAC) = total marketing & sales spend ÷ new customers acquired. Conversion rate = conversions ÷ visitors × 100. Email revenue = emails delivered × click rate × conversion rate × average order value. Use the free calculators below to run your own numbers in seconds — no signup, no spreadsheet.

Whether you're running Google Ads for your bar, sending email campaigns for your online shop, or handing out promotional products at events, these four calculators tell you what's actually working.

How to calculate advertising ROI (and why ROAS alone lies to you)

Most dashboards report ROAS (return on ad spend): revenue ÷ ad spend. A 4x ROAS sounds great — but if your product costs 40% of its price to make and ship, your true ROI is what's left after both the ad spend and the cost of goods. That's why the calculator asks for your cost of goods percentage and shows your break-even ROAS: at a 40% cost of goods you need at least 1.67x ROAS just to break even, and at 60% cost of goods you need 2.5x.

Worked example: $1,000 in ads generates $4,000 in sales. ROAS = 4.0x. At 40% cost of goods, profit = $4,000 × 0.60 − $1,000 = $1,400, so true ROI = 140%.

Customer acquisition cost (CAC): the number that decides your ad budget

CAC is simply everything you spent to win customers divided by the number of new customers you won. The benchmark that matters is the LTV:CAC ratio — a customer should be worth at least 3x what you paid to acquire them. If your ratio is below 3:1, you have two levers: pay less per customer (better targeting, cheaper channels, referrals) or make each customer worth more (repeat purchases, higher order values).

This is also where physical marketing quietly wins: a branded giveaway that costs about a dollar per unit and gets used for years can produce a far lower effective CAC than auction-priced ad clicks — we break down the math in the ROI of a $1 promo item.

Conversion rate: small percentage, huge leverage

Typical e-commerce stores convert 2–3% of visitors; landing pages for lead generation often run 5–15%. The reason conversion rate deserves its own calculator is leverage: at 5,000 monthly visitors and a $60 average order, moving from 2.5% to 3.0% conversion adds $1,500 a month in revenue with zero extra ad spend. Before buying more traffic, make sure the traffic you already have converts.

Email revenue: the channel you already paid for

Email consistently delivers among the highest ROI in marketing because the audience cost is already sunk. The funnel is: delivered → opened → clicked → purchased. Benchmarks in 2026: open rates of 35–45% (post-Apple-privacy opens are inflated, so treat them as directional), click rates of 1–3% of delivered, and click-to-purchase conversion of 5–10% for promotional sends. The metric to optimize is revenue per email — it makes campaigns of different sizes comparable.

FAQ

What is a good ROAS in 2026?

It depends entirely on your margins. A 4x ROAS is often quoted as "good," but a store with 30% cost of goods breaks even at 1.43x while a store with 70% cost of goods needs 3.33x. Calculate your break-even ROAS first, then judge campaigns against it.

What is a good customer acquisition cost?

There's no universal number — a good CAC is one your customer lifetime value supports at a ratio of at least 3:1. If a customer is worth $300 over their lifetime, a CAC up to $100 is sustainable.

What counts as a conversion?

Whatever action you're optimizing for: a purchase, a quote request, an email signup, a booked call. Just be consistent — don't compare a purchase conversion rate against a signup conversion rate.

Is ROI the same as ROAS?

No. ROAS is revenue ÷ ad spend and ignores product costs. ROI is profit ÷ ad spend and accounts for what the goods sold actually cost you. Campaigns can have a positive ROAS and a negative ROI.

How do promotional products fit into these metrics?

Treat them like any other channel: the spend is your unit cost × quantity, and the return is tracked with a QR code, coupon code, or dedicated landing page. Because items like drinkware and custom koozies keep generating impressions for years, their cost per impression is often a fraction of a cent.