Rank for it, orpay for it?
Paid search buys you the same lead every single month and stops the day you stop paying. SEO costs more up front, lags for months, then compounds into traffic you own. This calculator runs both lines forward over your horizon, shows the month SEO gets cheaper, and tells you which channel actually wins by the finish.
Your numbers
Leads you need from this channel each month.
What you pay for a click on paid search for this term.
Share of clicks that become a lead. Same page serves both channels.
Content, links, and agency or in-house cost per month.
How far out you're deciding. 12 is the usual planning window.
Months until SEO traffic reaches the full lead goal, then holds.
The verdict
Paid total
$120,000
$100 per lead, flat.
SEO total
$48,000
$51 per lead by horizon.
Break-even month
4
When SEO gets cheaper per lead.
Cheaper at horizon
$51
SEO, per lead
Paid / month
$10,000
SEO leads earned
950
Cumulative over horizon.
Total cost over 12 months
SEO costs more per lead until month 4, then it's cheaper for good. By month 12, SEO leads cost $51 each versus paid's flat $100.
Break-even month vs. your horizon
Month by month · cumulative cost
When the SEO line crosses under paid
| Month | Paid spent | SEO spent | SEO $/lead | Cheaper |
|---|---|---|---|---|
| Mo 1 | $10,000 | $4,000 | $240 | Paid |
| Mo 3 | $30,000 | $12,000 | $120 | Paid |
| Mo 5 | $50,000 | $20,000 | $80 | SEO |
| Mo 7 | $70,000 | $28,000 | $62 | SEO |
| Mo 9 | $90,000 | $36,000 | $55 | SEO |
| Mo 11 | $110,000 | $44,000 | $52 | SEO |
| Mo 12 | $120,000 | $48,000 | $51 | SEO |
Paid spends a flat $10,000 every month and its cost per lead never moves. SEO's cost per lead falls as its leads pile up — at month 4 it drops under paid and stays there. That crossover is the whole decision.
Sanity check · cost per lead, head to head
Flat vs. falling
Paid (rented)
Cost / lead
$100
Clicks / mo needed
2,500
Same price per lead forever. Stop paying and the leads stop the same day.
SEO (owned)
Cost / lead now
$51
Leads earned
950
950 leads for $48,000, and the per-lead cost keeps dropping after this.
A $0.79 median click is roughly what paid search costs across platforms — type your real CPC above. The higher your CPC and the lower your conversion rate, the faster SEO pays back; cheap clicks on a short horizon keep paid ahead.
Your move
Two lines on a chart. I tell you which one to fund.
100 leads/mo: paid $120,000 vs SEO $48,000 over 12 mo — SEO cheaper from month 4.
Send me your real CPC, conversion rate, and the terms you care about. In 30 minutes I'll tell you whether to pour into paid, commit to SEO, or run both in sequence — and which keywords to rank for first. Free, and you keep the plan whether you hire me or not.
Plain English
Renting leads vs. owning the road to them.
Paid search and SEO both end in the same place — a lead — but they buy it on opposite terms. Paid is a meter: you pay per click, you get traffic today, and the instant you stop the budget the leads stop with it. The cost per lead is flat and it never gets cheaper, because next month you start from zero again.
SEO is an asset. The money goes into content, links, and technical work that takes months to rank, so the first stretch looks like pure cost with little to show. But once those pages climb, they keep delivering traffic whether or not you spend more, and your effective cost per lead falls every month as the same investment is spread over a bigger and bigger pile of cumulative leads.
That's the real decision, and it's almost never 'which is better' — it's 'which is cheaper for my goal, over my horizon, given how long my SEO will take to land.' This calculator holds both honest: paid is instant but rented, SEO compounds but lags. It shows the total bill for each over your window and the exact month the SEO line crosses under paid.
The formula
Paid CPL = CPC ÷ conversion rate · SEO CPL = total SEO spend ÷ cumulative SEO leads
Need 100 leads/mo at a $4 CPC and a 4% click-to-lead rate: that's 2,500 clicks × $4 = $10,000/mo, or $100 per lead, forever. SEO at $4,000/mo ramping to the same 100 leads over 6 months costs $48,000 across a year but earns ~975 cumulative leads — about $49 per lead by month 12, and falling. Paid wins early; SEO wins the year.
What a click actually costs
Your break-even is driven by the paid cost per lead, and that's set by the click price on your channel. Cheap clicks make paid hard to beat; expensive clicks tilt the math toward SEO fast. Median CPC by platform, so you can sanity-check the number you typed:
| Platform | Median CPC |
|---|---|
| Google Ads | $4.66 |
| Facebook Ads | $0.77 |
| Instagram Ads | $0.68 |
| LinkedIn Ads | $5.78 |
| TikTok Ads | $0.22 |
| Pinterest Ads | $0.80 |
Source: Whatagraph / industry CPC data · 2025
The lines crossed (or didn't). Now what?
SEO never gets cheaper inside your horizon.
Either the window is too short for SEO to compound, or the SEO spend is too high for the lead goal. Lengthen the horizon, cut the monthly SEO bill, or accept that paid is the right call for this term right now.
Break-even lands very early.
Your paid cost per lead is brutal — usually a high CPC, a low conversion rate, or both. SEO pays for itself fast here. Fund the content and run paid only to cover the ramp gap.
Click-to-lead rate is under ~2%.
The page is the leak, and it taxes BOTH channels equally. Fix conversion before you pick a channel — every point you add lowers paid cost per lead and lifts SEO leads at the same time.
Cheap clicks, short horizon.
Paid wins and it's not close. Don't force SEO into a window where it can't compound. Buy the leads, prove the funnel, and revisit SEO once you're planning past a year.
How to actually run both
01Use paid to fund the ramp
Run paid for leads today while SEO climbs, then taper paid spend on terms you've started ranking for. Paid covers the lag; SEO retires the bill.
02Fix the page first
Click-to-lead rate divides into both channels. A page that converts 2% → 4% halves paid cost per lead and doubles SEO leads on the same spend — the single best lever here.
03Pick terms paid is bleeding on
Your most expensive, highest-volume paid keywords are exactly the ones SEO should target. The higher the CPC, the faster ranking pays back.
04Build assets, not posts
Money pages and comparison content rank durably and convert. Thin blog volume inflates SEO cost without moving the cumulative-lead line.
05Set a real ramp expectation
Most SEO needs 4–9 months to deliver meaningful traffic on a competitive term. Modeling a 2-month ramp just lies to you — be honest in the input.
06Keep paid on bottom-funnel
Even after SEO lands, keep paid on high-intent, transactional queries where the lead is worth the click. Let SEO own the cheaper, broader top.
07Re-run this quarterly
As pages rank, your real SEO cost per lead drops below the model. Update the ramp and horizon each quarter and shift budget to whichever line is actually cheaper.
The vocabulary
- CPC
- Cost per click: what you pay each time someone clicks your paid search ad.
- Click-to-lead rate
- Share of clicks that convert into a lead on the landing page. Applies equally to paid and organic traffic.
- Paid cost per lead
- CPC ÷ click-to-lead rate. Flat over time — paid never compounds.
- SEO ramp
- The months it takes SEO to reach full target traffic. Before the ramp ends, SEO under-delivers leads.
- Cumulative SEO leads
- Running total of leads SEO has produced across the horizon. The denominator that drives SEO's falling cost per lead.
- Break-even month
- The first month SEO's cumulative cost per lead drops below the flat paid cost per lead.
SEO vs paid, straight answers
Eventually, usually — but not at first. Paid has a flat cost per lead that never improves; SEO costs more up front and lags for months, then its cost per lead falls every month as the same spend is spread over more cumulative leads. Whether it's cheaper for you depends on your horizon and ramp: this tool finds the exact month the SEO line crosses under paid.
Keep going
A calculator tells you what. A call tells you what to do about it.
Send me the account behind these numbers. I'll tell you straight where the money's leaking and what I'd fix first — free, and you keep it whether you hire me or not.