--- title: "Cold Email Calculator: Volume, Inboxes & Domains | Prosyo" description: "Free cold email calculator: work back from your meeting goal to the prospects, daily emails, sending inboxes and domains you need. See the maths." url: "https://prosyo.com/fr/tools/cold-email-volume-calculator/" image: "https://prosyo.com/wp-content/uploads/2026/10/cropped-Prosyo-Icon-Transparent-1.png" language: "fr" --- Free Tools # Cold Email Volume & Inbox Calculator Work back from your meeting goal to the prospects, daily sends, inboxes and domains you need. Cold Email Volume & Inbox Calculator Instant · free ## What is a cold email volume calculator? A cold email volume calculator works backwards from the number of meetings you want to the prospects, emails, sending inboxes and domains you need to get there. Most outbound plans start the wrong way round (“we will send 500 emails a day and see what happens”) and end up either overloading a few inboxes, which hurts deliverability, or under-sending and missing the goal. This free calculator takes six inputs (your monthly meeting goal, reply rate, the share of replies that become meetings, emails per prospect, sends per inbox per day and sending days per month) and shows the replies, new prospects, monthly and daily emails, inboxes and domains you need. It also explains each step of the maths, so you can see which assumption matters most. ## Key takeaways - Work backwards: meetings, then replies, then prospects, then emails, then inboxes. - Keep each inbox to a moderate daily volume and add inboxes to scale. - Use two or three inboxes per secondary domain. - Reply rate is the biggest lever: doubling it halves every infrastructure number. - Check that enough good-fit prospects exist before planning high volume. ## How to use the calculator 1. **Set your meeting goal** for a month. 2. **Enter your reply rate.** If you do not know it yet, start with a conservative number for a new campaign, then replace it with your real data after a few weeks. 3. **Enter the share of replies that book a meeting.** Not every reply is positive; many are “not now” or “wrong person”. 4. **Enter emails per prospect**, meaning the number of email steps in your sequence. 5. **Set sends per inbox per day**, a safe daily volume for each mailbox. 6. **Set sending days per month**, usually about 22 working days. 7. **Press “Calculate”** and read the tiles and the explanation. ## The maths, step by step 1. **Replies needed** = meetings ÷ share of replies that become meetings. Twenty meetings at 30% means about 67 replies. 2. **Prospects needed** = replies ÷ reply rate. Sixty-seven replies at 4% means about 1,667 new prospects a month. 3. **Emails per month** = prospects × emails per prospect. At 3 emails each, about 5,000 emails. 4. **Emails per day** = emails per month ÷ sending days. Over 22 days, about 227 a day. 5. **Inboxes** = emails per day ÷ sends per inbox, rounded up. At 30 each, 8 inboxes. 6. **Domains** = inboxes ÷ 3, rounded up. Three domains. The calculator assumes that every prospect receives the full sequence, which slightly overstates volume because people who reply stop receiving follow-ups. It is a planning estimate, deliberately on the safe side. ## Choosing realistic inputs ### Reply rate Reply rates vary enormously with targeting, relevance and channel. Generic, high-volume campaigns to loosely targeted lists see low single-digit reply rates or less; tightly targeted, personalised campaigns to people with a clear reason to care do far better. Use your own data when you have it. If you are starting fresh, plan with a cautious figure and treat anything better as upside. ### Replies that become meetings A reply is not a meeting. Some replies are objections, referrals or “not now”. Track your own positive-reply rate; the [Objection Reply Generator](https://prosyo.com/tools/objection-handler/) helps you turn more of the in-between replies into conversations. ### Emails per prospect Many cold sequences use two to four emails over two to three weeks, often alongside LinkedIn steps. More emails reach more people but each extra step adds volume and complaint risk; make every follow-up add something new. ### Sends per inbox per day Many teams keep cold sends to roughly 30 to 50 a day per inbox, with warm-up running alongside, and lower for brand-new inboxes. Higher volumes from one mailbox raise the risk that providers throttle or filter it. Spreading volume across more inboxes is the standard way to scale safely. ### Inboxes per domain The calculator assumes three inboxes per domain, a common setup that keeps each domain’s total volume moderate. Some teams use two; few use more than five on one domain for cold email. ## Why spread volume across inboxes and domains Mailbox providers judge reputation per domain and, in part, per mailbox. A single inbox sending 300 cold emails a day looks nothing like normal human email and attracts filtering. Thirty inboxes sending 10 each looks like a company of people writing to contacts. Using separate secondary domains for outreach keeps your main domain, the one your customers, invoices and team depend on, completely separate from the risks of cold email. ## Setting up the infrastructure the calculator gives you 1. **Buy secondary domains** close to your brand, such as `getacme.com` or `acmehq.com`. Point their websites at your main site. 2. **Create the inboxes** with real names, photos and signatures in Google Workspace or Microsoft 365. 3. **Publish SPF, DKIM and DMARC** on each domain and confirm with the [Domain Health Checker](https://prosyo.com/tools/domain-health-checker/). 4. **Warm up** each inbox for two to four weeks; the [Warm-up Planner](https://prosyo.com/tools/email-warmup-planner/) gives a day-by-day ramp. 5. **Verify every list** with the [Email Verifier](https://prosyo.com/tools/email-verifier/) before sending. 6. **Start below the target** and increase as replies and bounce rates stay healthy. ## Worked examples | Scenario | Inputs | Result | | --- | --- | --- | | Founder doing outbound part-time | 8 meetings, 5% reply, 35% to meeting, 3 emails, 25 per inbox, 22 days | About 457 prospects, 1,371 emails, 62 a day, 3 inboxes on 1 domain | | Small sales team | 20 meetings, 4% reply, 30% to meeting, 3 emails, 30 per inbox, 22 days | About 1,667 prospects, 5,000 emails, 227 a day, 8 inboxes on 3 domains | | Agency running several clients | 60 meetings, 3% reply, 30% to meeting, 3 emails, 30 per inbox, 22 days | About 6,667 prospects, 20,000 emails, 909 a day, 31 inboxes on 11 domains | The third row shows why improving reply rate matters more than adding volume: moving from 3% to 6% halves every infrastructure number. ## The lever that matters most Change one input at a time and watch the results. In almost every scenario, **reply rate** moves the infrastructure needs more than anything else, and reply rate depends on targeting and relevance, not volume. Doubling reply rate halves the prospects, emails, inboxes and domains you need. That is cheaper, safer for deliverability and kinder to the people you write to. Sharpen targeting with the [ICP Generator](https://prosyo.com/tools/icp-generator/) and openers with the [Icebreaker Generator](https://prosyo.com/tools/linkedin-icebreaker-generator/) before you buy more domains. ## Planning for list size, not just volume The calculator tells you how many new prospects you need each month. The next question is whether that many good-fit prospects exist. If your ideal customer is “heads of revenue at US fintech companies with 50 to 500 employees”, the total market might be a few thousand people. Contacting 1,700 a month would exhaust it within a season and burn through your best accounts with whatever message you happen to be testing. Before scaling: - **Estimate your total addressable list** with filters in your data source or LinkedIn. - **Divide it by monthly prospects** to see how many months it lasts. - **Prioritise by signal**: people showing buying intent, hiring, recently funded, or engaging with your content should be contacted first. - **Leave room to re-contact** later with a new angle, rather than emailing everyone once with an untested message. If the list is small, raise reply rate instead of volume: tighter targeting and more specific messages. ## Adding LinkedIn to the maths LinkedIn steps reach prospects without adding email volume, and LinkedIn has its own per-account limits on invitations and messages. In a multichannel sequence, a share of your replies will come from LinkedIn, so the email volume needed for the same meeting goal falls. A simple way to plan: run the calculator for email alone, then reduce the prospects needed by the share of replies you expect from LinkedIn once you have data, while keeping LinkedIn activity within safe daily limits per account. ## Seasonality and timing Reply rates change through the year. Late December and the main summer holiday weeks in each region are usually quieter; January and September often see buyers planning new projects. Plan volume across the year rather than assuming every month is the same, and keep your sending steady through quiet periods rather than stopping and restarting, which is harder on inbox reputation than a lower, consistent volume. ## Budgeting the infrastructure Each sending inbox is a paid mailbox seat with your provider, and each domain is a yearly registration. The numbers from the calculator translate directly into a monthly budget: inboxes times your provider’s per-seat price, plus domains, plus any warm-up and outreach tool costs. Compare that with the value of the meetings in the [Outbound ROI Calculator](https://prosyo.com/tools/outbound-roi-calculator/); for most B2B offers the infrastructure is a small fraction of the value of one closed deal. ## Common planning mistakes - **Planning with optimistic reply rates.** Start conservative and adjust with real data. - **Forgetting warm-up time.** New inboxes need several weeks before they carry full volume. - **Putting too many inboxes on one domain.** One problem then affects all of them. - **Sending from the main company domain.** Keep cold email on secondary domains. - **Ignoring LinkedIn.** A second channel reaches people email cannot, without adding email volume. ## Glossary - **Reply rate**: unique prospects who replied, divided by prospects contacted. - **Positive reply rate**: replies showing interest, divided by prospects contacted. - **Sequence**: the series of steps (emails, LinkedIn actions) each prospect receives. - **Sending inbox**: a mailbox used to send outreach. - **Secondary domain**: a domain used for outreach, separate from the main company domain. ## From the calculator to a weekly routine A monthly number is easier to manage as a weekly rhythm. With the default example (about 1,667 new prospects and 5,000 emails a month across 8 inboxes), a working week looks like this: - **Monday**: add roughly 380 to 420 new, verified prospects to sequences, spread across inboxes. - **Every weekday**: each inbox sends around 28 to 30 cold emails, spaced through working hours, with warm-up running. - **Daily**: answer every reply the same day; positive replies first. - **Friday**: review bounce rate, replies and meetings by campaign and audience; pause anything with bounces above 2% or no replies. - **Monthly**: rerun the [Domain Health Checker](https://prosyo.com/tools/domain-health-checker/) on every sending domain and replace your assumptions here with real data. ## How multichannel outreach changes the numbers When LinkedIn and email run together, the same person sees your name in two places, and each channel catches people the other misses. In practice that tends to lift reply rate, which, as the calculator shows, reduces every infrastructure number. It also spreads activity across channels with separate limits, so no single inbox or account carries the whole plan. ## How Prosyo helps Prosyo runs LinkedIn and email in one sequence from your own accounts, keeps every account inside safe daily limits automatically, and stops the moment someone replies. It finds and verifies prospects who fit your ideal customer, writes personal openers and drafts every reply. [Try it free for 7 days](https://prosyo.com/pricing/). ## Related free tools These tools are often used together with the Volume and Inbox Calculator. All of them are free, and the checkers and calculators run instantly in your browser. - [Warm-up Planner](https://prosyo.com/tools/email-warmup-planner/): Get a day-by-day warm-up and ramp schedule for a new inbox or domain. - [Outbound ROI Calculator](https://prosyo.com/tools/outbound-roi-calculator/): Estimate the replies, meetings, pipeline, revenue and cost per meeting your outbound should produce. - [Domain Health Checker](https://prosyo.com/tools/domain-health-checker/): Score your sending domain on MX, SPF, DKIM, DMARC, BIMI, MTA-STS and blocklists in one click, with a fix for everything that fails. - [ICP Generator](https://prosyo.com/tools/icp-generator/): Turn your offer into a focused ideal customer profile with triggers, pains and disqualifiers. ## Frequently asked questions ### How many cold emails should I send per day? Per inbox, many teams keep cold sends to around 30 to 50 a day, lower for new inboxes. To send more in total, add inboxes and domains rather than increasing volume per inbox. ### How many inboxes do I need for cold email? Divide your daily email volume by your safe sends per inbox. For example, 227 emails a day at 30 per inbox needs 8 inboxes. The calculator works this out from your meeting goal. ### How many inboxes should I put on one domain? Commonly two or three. That keeps each domain’s total daily volume moderate so one problem never affects too much of your sending. ### How do I calculate how many prospects I need? Divide your meeting goal by the share of replies that become meetings to get replies needed, then divide by your reply rate. Twenty meetings at 30% and a 4% reply rate needs about 1,667 prospects. ### What is a good cold email reply rate? It depends heavily on targeting and relevance. Use your own data once you have it. Better targeting and more specific messages raise reply rates far more than extra volume does. ### Should I send cold email from my main domain? Most teams use separate secondary domains for cold outreach, so any deliverability problem never affects the domain your customers, invoices and team rely on. ### Is this calculator free? Yes, with no sign-up. It runs in your browser. ## Ready to Accelerate Your Growth? Launch smarter campaigns, convert more leads, and scale your business with ease — all in one place. [Get Started Now](https://prosyo.com/fr/) [Book a Demo](https://prosyo.com/fr/pricing/)