The calculator above just multiplies the seven numbers you enter. It doesn't know your product, your subreddit, or your close rate, so move one slider at a time and watch which one swings the result. Whether Reddit is worth your time depends on how well your product fits the communities you'd reply in, not on how many replies you post.
How to use it
The widget has seven sliders, in the order they feed into each other: how often you post, how many people show up, how many of them convert twice over, what they're worth, how long they stay, and how much time the whole thing costs you. Each slider means this, and here's where to source the number.
Replies per week. How many Reddit comments you'll realistically write and post yourself, week after week. Start low. Five to ten is a normal pace for a solo founder who's also running the product. If you've never posted, use the subreddit rules checker on two or three communities first, so this number reflects how many allow a reply worth posting, not a wish.
Visits per reply in the first month. How many people click through from a single comment in its first month. You won't know this until you've posted a few and checked your own analytics for referral traffic from reddit.com. Until then, treat the default as a placeholder, not a forecast.
Visit to signup %. The share of those visitors who sign up for something, free trial or waitlist. Pull this from your own site analytics, not an industry average. If you don't have a number yet, use your worst month, not your best one.
Signup to paid %. Your actual trial-to-paid conversion rate. Every product has a different one. If you're pre-launch, use whatever number you're already assuming in a spreadsheet somewhere. That assumption is doing the same job here.
Revenue per customer per month. Your real monthly price, or your average revenue per account if you have several plans.
Months a customer stays. Your average customer lifetime in months, meaning how long someone keeps paying before they churn. If you don't track this yet, a cautious starting point is however many months your refund or cancellation window covers, doubled.
Minutes per reply. How long it takes you to find a good thread, read it, and write a reply worth posting, not a copy-paste line. Time yourself on the next one you post. It's almost always longer than you'd guess.
None of these seven defaults are Radar's numbers, a study's numbers, or a promise. They're a starting point so the calculator has something to multiply. Replace them with your own as soon as you have them, and come back and update them again once you've posted a few replies and have real numbers instead of assumptions. The calculator is only as honest as what you type into it.
How the math works
The calculator runs the same eight steps every time, in order:
- Replies posted per month = replies per week times 4.33 (the average number of weeks in a month).
- Visits per month = replies posted per month times visits per reply.
- Signups per month = visits per month times the visit to signup rate.
- New paying customers per month = signups per month times the signup to paid rate.
- New monthly revenue = new paying customers per month times revenue per customer per month.
- Lifetime value of that cohort = new monthly revenue times months a customer stays.
- Hours spent = minutes per reply times replies posted per month, converted to hours.
- Hours per customer = hours spent divided by new paying customers per month.
That's the whole tool. No hidden multiplier, no adjustment for how good your reply is, no correction for which subreddit you posted in. It just does the arithmetic on what you typed in. The gap between this and your real result is entirely made of things the calculator can't see: fit, timing, whether the thread was even live when you replied.
Which input matters most
A worked example using the calculator's defaults: 10 replies a week, 8 visits per reply, a 5% visit to signup rate, a 5% signup to paid rate, $29 a month in revenue per customer, an 8 month average customer lifetime, and 8 minutes per reply.
These are the calculator's placeholder numbers, not a forecast and not a result anyone should expect. Treat the table below as a demonstration of the arithmetic, nothing else.
| Step | Calculation | Result |
|---|---|---|
| Replies per month | 10 × 4.33 | 43.3 |
| Visits per month | 43.3 × 8 | 346.4 |
| Signups per month | 346.4 × 5% | 17.3 |
| New paying customers | 17.3 × 5% | 0.87 |
| New monthly revenue | 0.87 × $29 | $25.11 |
| Cohort lifetime value | $25.11 × 8 | $200.86 |
| Hours spent | 43.3 × 8 minutes | 5.8 hours |
| Hours per customer | 5.8 ÷ 0.87 | 6.7 hours |
Now change one input at a time and watch what happens to hours per customer, the number that tells you whether you're getting more efficient or just doing more work.
Double the replies, 20 a week instead of 10. Everything downstream doubles too: 86.6 replies a month, 692.8 visits, 34.6 signups, 1.73 new customers, $50.23 in new monthly revenue, 11.5 hours spent. Hours per customer: 11.5 ÷ 1.73, still 6.7 hours. You did twice the work for twice the customers. The ratio didn't move.
Double the signup rate instead, 10% instead of 5%, replies held at 10 a week. Signups jump to 34.6, new customers to 1.73, new monthly revenue to $50.23, same as doubling replies. But hours spent stays at 5.8, because you didn't post more, you just converted better. Hours per customer: 5.8 ÷ 1.73, which is 3.3 hours. Half of what it was.
Same revenue gain, half the time cost. This is why signup rate, paid rate, and reply fit matter more than volume. More replies scale results and workload together. A better-targeted reply scales results without extra work.
Why more replies is the wrong lever
Radar doesn't ship reply quotas for a reason this calculator shows. More volume gets you banned. Better fit gets you customers.
The product enforces this directly: one product mention per subreddit per run, then a cooldown before it'll suggest that subreddit again. Roughly half the replies Radar drafts never pitch the product at all, they answer the question and stop, because the community's rules or the thread's context don't call for a mention. That's the point of drafting slowly. A pitch that doesn't fit costs you the account before it earns you a customer.
I know this from the inside. I got a 28-day ban from r/SaaS, then a permanent ban from r/startups, both for replies I thought were helpful and that still broke a rule I hadn't read. Neither ban came from spamming. Both came from posting in a community whose rules I hadn't checked. The math in this calculator will tell you that doubling your reply count doubles your customers. It won't tell you that the eleventh reply in a community that only tolerates one gets you banned instead.
The compounding part the calculator leaves out
Every number above is a monthly snapshot, assuming replies are done working after the month they go live. But Reddit threads don't work that way.
A good comment on Reddit keeps showing up in that thread for as long as the thread exists, which for a well-ranked post can be years. Reddit threads rank on Google for the questions people search, and they get pulled into AI-generated answers on tools like Perplexity when they're a good match for the question asked. That's the part of the return this calculator can't multiply for you, because it isn't a rate, it's a tail. Radar measures it per thread: where the thread ranks on Google for the question behind it, and whether Perplexity is citing it. Neither of those numbers promises you a conversion. They just tell you a reply is still doing something months after you wrote it, instead of scrolling off Reddit's homepage and disappearing.
That tail is also why "replies per week" is the weakest lever in the calculator even though it feels like the most direct one. A reply you post today isn't done working after this month's visits get counted. If it ranks, it keeps sending people your way in month two, month six, whenever someone searches the same question and finds the thread instead of your ad. The calculator has no slider for that, because there's no honest rate to multiply it by. It shows up as a gap between what the sliders predict and what you see over a year, and that gap is usually in your favor, not against it.
If you want to see what that finds for your own product, running Radar's real scan is free. It reads your site, matches it to communities where it fits, and shows three days of live threads with a reply ready to copy. Scan my site free. No card.
Comparing Reddit to other channels honestly
Cold email and paid ads are measured in money: cost per send, cost per click, cost per lead. Reddit is measured in time: minutes per reply, hours per customer. That's the actual unit. You're not paying Reddit for placement. You're paying with the time it takes to find the right thread and write something worth reading.
That's what the hours per customer output is for. It converts a channel that has no invoice into a number you can hold up against your own hourly cost, or against what you're paying per lead somewhere else. If an hour of your time is worth less to you right now than an hour of an ads budget, Reddit's cost structure works in your favor. If your time is the scarcest thing you have, the calculator will tell you that too, since hours per customer only goes down when your fit or conversion improves, not when you just post more.
This is also why the calculator refuses to output a dollar cost for a Reddit reply. There isn't one. There's a time cost, and what you decide that time is worth is a judgment call the calculator can't make for you.
It also means the two channels fail differently. An ads budget that isn't working stops spending the moment you turn it off, and the loss is capped at whatever you spent. Time spent on a Reddit reply that doesn't land is a sunk cost either way, but it doesn't carry the same downside if you check the community's rules first, since a reply that helps without pitching still cost you the minutes and gave you nothing back but goodwill. The failure mode to watch for isn't wasted time, it's a reply that breaks a rule you didn't check and costs you the account. That risk doesn't show up in this calculator at all. It shows up in the subreddit rules checker instead.
What Radar charges, for the cost side
If you want the cash side of this equation for what Radar itself costs: $29 a month or $290 a year, flat, every product on the account included, no reply quotas of any kind. A $399 one-time founding membership covers the first 50 seats; after those sell out, new monthly signups are $39. Every plan includes 3 tracked keywords per product for the mentions scan. Full details are on the pricing page.
None of that is in the calculator, because the calculator is about your Reddit time, not about what any particular tool costs. But if you're weighing Reddit against a paid channel, this is the number to weigh it against.
FAQ
Is Reddit marketing worth it?
It depends on whether your product fits the communities you'd be replying in, not on how much time you put in. A product that solves a problem people are actively asking about in a subreddit that allows a disclosed founder reply can get real signups from a handful of well-placed comments. A product with no natural fit won't get there no matter how many replies you post, and posting anyway is how founders get banned.
What's a realistic Reddit marketing ROI?
There's no single realistic number, because it depends entirely on your own visit-to-signup rate, your signup-to-paid rate, and your price. Use the calculator with your own analytics numbers instead of the defaults, then check back after a month of real posting and update the sliders with what happened.
How much does Reddit lead generation cost?
Mostly your time, not cash. Reddit doesn't charge for a reply the way an ad platform charges for a click. The real cost is the minutes it takes to find a thread worth replying to and write something worth reading, which is what the calculator's hours-spent and hours-per-customer outputs are built to show.
Is Reddit marketing better than cold email?
They're different kinds of cost, which makes a direct comparison hard. Cold email has a cash cost per send and scales by spending more money. Reddit has a time cost per reply and scales by getting better at picking threads and writing to them, not by spending more. Whether one beats the other depends on whether your time or your budget is the scarcer resource right now.
How many Reddit replies does it take to get a customer?
Run the calculator with your own numbers and read the "new paying customers" output, since it depends on your visit rate and your two conversion rates, which vary a lot by product. The worked example on this page, using the calculator's defaults, needed roughly 43 replies in a month to reach under one new paying customer. That's an illustration of the arithmetic, not a benchmark to expect.
Does posting more replies on Reddit always help?
No. Doubling your reply count doubles your customers and doubles your hours spent by the same amount, so your hours-per-customer ratio doesn't improve, you're just doing more work for proportionally more result. Doubling your signup rate instead gets you the same gain in customers without any extra hours. Fit and conversion move your efficiency. Volume alone doesn't, and past a point it gets you banned instead. That's also why Radar checks each community's real rules with the subreddit rules checker and runs every draft through checks before you see it with the reply checker, rather than pushing you toward posting more. More on why I built it that way is on the blog: why I built Radar.