Google Ads: share of total spend
67%
Google Ads: share of assumed leads
40%
Google Ads: spend share minus lead share (gap to check)
27pts
This calculator does simple ratio math: it divides each channel's spend by total spend, and each channel's guessed leads by total guessed leads, then subtracts the two percentages. It assumes the numbers you enter are accurate guesses, it does not verify or measure anything about your actual traffic, calls, or ad accounts. A large gap is a prompt to check your assumption, not proof that a channel is over or under performing.
Stop estimating. See the real source behind every lead.
Lead Recorder attaches the actual channel, ad, or keyword to every form fill and call, so this number becomes a fact, not a guess.
Try Lead Recorder freeWhy it matters
Most small business owners split ad spend based on which channel feels like it's working, not on which channel leads actually came from. If a channel takes most of your budget but you can only guess at a small share of leads from it, that gap is the exact reason to start tagging leads by source instead of estimating.
Reading the gap number
The default example on this calculator puts $1,200 a month into Google Ads and guesses that channel brings in 8 leads, against $600 and 3 guessed leads from Facebook, plus 9 guessed from referral or direct. Run through the math and Google Ads sits at 67% of spend but only 40% of assumed leads, a 27 point gap. That gap is not a verdict on Google Ads, it is a flag that the guess and the budget disagree with each other by a wide margin.
The size of the gap matters more than its direction. A small gap, a few points either way, is normal rounding in anyone's head. A gap over 20 points, like the 27pts in the example, means you are funding a channel at more than half again the rate you think it earns, or the reverse. Either way the honest next step is to find out what actually happened to those leads, not to shift budget on the strength of a guess you already know is shaky.
Worth being clear about what this number cannot do. It cannot tell you whether the 8 leads you guessed from Google Ads is close to correct, because you typed that number in, the calculator did not measure it. It only tells you that your own two guesses, spend share and lead share, don't line up. Closing the gap between belief and budget starts with knowing where leads actually came from, not with adjusting the guess until the math looks better.
Why the guess is usually wrong in a specific direction
Lead Recorder's own tracked data, 1,145 leads across 9 Australian small-business websites over about 11 weeks, shows 54% of leads came from a channel the business wasn't paying for at all: organic search, direct, or referral. The remaining 46% came through paid ads. Owners who assume most of their leads trace back to whichever ad they're actively running tend to undercount the free channels, which is exactly the kind of mistake this calculator is built to surface.
Within paid, Google Ads accounted for 44.6% of leads in that dataset, well ahead of any other single paid channel. That's useful context if your own guessed Google Ads leads number feels low against a high spend figure, because it may genuinely be under-credited rather than underperforming. Organic search took 23.7%, direct 19.4%, and referral 9.2%, three channels with no line item in most ad budgets at all.
None of this tells you what your specific site's split is. It's one dataset from one agency's client base, and your business may look nothing like it. What it does show is that guessing tends to miss the unpaid side of the ledger by a wide margin, which is a reasonable thing to check for in your own inputs before you trust the gap number too far.
Why owners guess instead of check
Ruler Analytics found that 62% of marketers using phone numbers to drive leads say they struggle to track inbound calls back to a source, and 53.3% name limited understanding of attribution as their single biggest challenge (Ruler Analytics, 2021). That's not a small-business problem specifically, it's the same gap this calculator is built around: people know the phone rings, they don't know which ad, page, or search made it ring. Lead Recorder addresses the click-to-call part of that by tagging when someone taps a phone number on your site and attributing that click to the traffic source that brought them there. It does not record or transcribe the call itself, it only tells you the click happened and where the visitor came from.
The bigger business version of the same problem shows up in HubSpot's State of Inbound, where 40% of marketers say proving the ROI of their marketing activities is a top challenge, and in Econsultancy's attribution study with AdRoll, where 70% of businesses say they struggle to act on the attribution insights they already have, out of 987 practitioners surveyed. Having the data and acting on it are two different problems. This calculator only addresses the first one: it puts your assumption in front of you next to your spend, so the disagreement is visible instead of buried in a spreadsheet you never open.
One more limit worth stating plainly. Nineteen percent of leads in Lead Recorder's tracked data show up as Direct, with no referrer and no UTM information, even with tracking installed. Some leads will never resolve to a clean source no matter how good your tagging is, browsers and privacy settings block some referrer data outright. The goal isn't a perfect attribution number, it's a smaller gap between what you fund and what you can actually trace.
The methodology, in full
No hidden formula: here's exactly what this calculator assumes and why.
Where do the default numbers come from?
They are just starting values so you can see how the calculator works before you put your own numbers in. They are not measured data or a claim about typical spend.
What does the gap number actually mean?
It's the difference between the percentage of your budget going to a channel and the percentage of leads you'd guess that channel produced. A large gap, in either direction, flags a channel worth checking properly rather than estimating.
Does this tell me my real lead sources?
No. Every lead number here is a guess you type in yourself. The calculator only compares your guesses against your spend, it doesn't detect or verify where any lead actually came from. Lead Recorder tags each form fill, click-to-call tap, or booking with its real source, so you can replace the guess with a number you can stand behind.
Why isn't call tracking or referrer data built into this?
This tool is deliberately just arithmetic on the numbers you provide. It doesn't read your website traffic, your ad accounts, or your phone logs. If you want the actual split, that needs tracking in place, not a spreadsheet exercise.
How should I use this with real numbers?
Replace the guesses with your actual monthly spend per channel, then replace the lead guesses with your honest best estimate, gut feeling included. The point isn't precision, it's noticing which channel has the widest gap between money in and leads you can point to.
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Turn the estimate into an answer
Lead Recorder captures the actual source behind every form fill and call, so you're reporting what happened, not what a calculator assumes.
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