# Cold email calculator > Works back from the meetings you want to the people to contact and emails to send. Free, no signup. Runs in your browser. Nothing you type is sent to us. **Cold email calculator. Work back from the meetings you want, in seconds, no signup.** Use it at https://tools.joinvalley.co/cold-email-calculator ## How it works It works backwards from the meetings you want. People to contact = meetings ÷ (reply rate × share of replies that are interested × share of those that book). Emails = people × emails per person. Everything runs in your browser, and nothing you type is sent to us. The rates are yours. The page opens on an example so the numbers aren't blank, but it isn't a benchmark: put in what your own sends show, or a guess you can check against them later. It flags two limits Google publishes: 2,000 messages a day per Google Workspace user, counted over a rolling 24 hours, and the bulk sender rules that apply once you send more than 5,000 messages a day to Gmail accounts. Then the infrastructure: mailboxes = emails a day ÷ what one mailbox sends a day (your cap), and domains = mailboxes ÷ mailboxes per domain. Add what a mailbox costs you and it totals the month. The caps are yours to set; we don't recommend a number. The table shows the same goal at other reply rates. Every time the reply rate doubles, the people, emails and mailboxes you need halve, which is why we'd work on who you write to and what you say before sending more. ## Sources - [Google Workspace Help: Gmail sending limits in Google Workspace](https://knowledge.workspace.google.com/admin/gmail/gmail-sending-limits-in-google-workspace) (read 2026-10-15) - [Google's email sender guidelines (Gmail Help)](https://support.google.com/a/answer/81126) (read 2026-10-14) ## Questions people ask ### How many cold emails does it take to book a meeting? Divide 1 by your reply rate times the share of replies that are interested times the share of those that book. With the example's 5%, 40% and 50%, that's 100 people per meeting, or 300 emails at 3 emails per person. ### How do I calculate how many leads I need for outbound? Leads to contact = meetings you want ÷ (reply rate × interested rate × booking rate). For 10 meetings at 5%, 40% and 50%, that's 1,000 people a month. ### How many mailboxes do I need for cold email? Divide the emails you send a day by what one mailbox sends a day. With the example's 150 emails a day and a cap of 30 per mailbox, that's 5 mailboxes, or 3 domains at 2 mailboxes each. The cap is your call; Google Workspace's own limit is 2,000 messages a day per user. ### What is a good cold email reply rate? No mail provider or standards body publishes one, so measure your own. Valley reports 15-45% reply rates, against a category average of about 2%. ### How many emails can I send a day from Google Workspace? Google's help page puts it at 2,000 messages a day per user, 1,500 for mail merge and 500 on a trial account, counted over a rolling 24 hours. We read it on 15 Oct 2026. ### When do Gmail's bulk sender rules apply? When you send more than 5,000 messages a day to Gmail accounts. Google then asks for SPF, DKIM and DMARC, one-click unsubscribe on marketing email, and a spam rate kept under 0.3%. ### Is it better to send more emails or raise my reply rate? Raise the reply rate first. Doubling it halves the people and emails you need for the same meetings, and sending more to the wrong people tends to bring complaints, not replies. That's our view. ### How does the calculator count follow-ups? It counts every email in your sequence for every person, so the email total is a ceiling. People who reply early stop getting follow-ups, so you'll usually send a little less. ### Is this cold email calculator free? Yes. It's free, needs no signup and runs in your browser, so nothing you type is sent to us or stored. ## Related tools - [SPF, DKIM and DMARC checker](https://tools.joinvalley.co/spf-dkim-dmarc-checker): Checks a domain's SPF, DKIM and DMARC records against Gmail and Yahoo's sender rules. - [Email spam checker](https://tools.joinvalley.co/email-spam-checker): Scores a cold email out of 100 and flags links, money signs, em dashes and merge tags. - [LinkedIn X-ray search builder](https://tools.joinvalley.co/linkedin-x-ray-search): Builds a Google search that finds LinkedIn profiles by job title, company and city. ## Next step Want replies, not just clean copy? Valley finds buyers showing real buying signals and messages them across email and LinkedIn. [Valley](https://www.joinvalley.co/?utm_source=tools_suite) Shelf: [06 Outbound planning](https://tools.joinvalley.co/outbound-planning) --- Tools by Valley, made by [Valley](https://www.joinvalley.co/?utm_source=tools_suite). HTML version: https://tools.joinvalley.co/cold-email-calculator