The Cost of Slow Response to Sales Enquiries: A Calculator You Can Fill In With Your Own Numbers

BOTrento Team12 October 20269 min read

The formula: four inputs, one monthly figure

Think of the cost of a slow reply as revenue that was within reach and slipped away. The model has four core inputs and two optional ones:

• E: qualified enquiries per month (real requests, not spam or job applications)
• L: the share of those enquiries lost because of delay, not because of price or fit
• W: your normal win rate on enquiries you answer promptly
• V: average order value, in euros excl. VAT
• M: gross margin on a typical order (optional, but more honest than revenue)
• H × R: hours per month spent chasing stale enquiries × internal hourly cost (optional)

The calculation:

Lost revenue per month = E × L × W × V
Lost margin per month = E × L × W × V × M
Total monthly cost of delay = lost margin + (H × R)

W is in the formula because not every enquiry you lost to delay would have become an order. A quick reply only gives you the same chance as your other prompt replies. Leaving W out is the most common way people overstate the problem.

How to estimate each input from your own inbox

Use a recent period that looks like a normal month for you. If you have a busy season, as many event and production companies do, work out a peak month and a quiet month separately.

Step 1: Count qualified enquiries (E)

Go through your sales inbox, or the shared address your enquiries arrive at, and count new requests for a quote, availability or a call. Leave out existing clients' routine orders. If you log enquiries in Pipedrive or HubSpot, export new deals by creation date. Then compare that number with the inbox, because enquiries that never made it into the CRM are often the ones that got answered late.

Step 2: Mark the ones lost to delay (L)

This is the input that matters most, and it takes the most judgement. For each enquiry that didn't become an order, check the thread and put it in one of three groups:

1. Clearly lost to delay: the client said they had already booked elsewhere, or went silent after a reply that came noticeably later than usual
2. Lost for other reasons: price, wrong fit, project cancelled
3. Unclear: no reply and nothing to go on

L is group 1 divided by E. Keep group 3 separate and run the calculation twice, once without it and once with half of it. That gives you a cautious figure and an upper figure.

Step 3: Your win rate on prompt replies (W)

Take only the enquiries answered quickly by your own standard, such as the same working day, and divide the orders by the enquiries. Don't use your overall win rate, because the slow replies are already pulling it down.

Step 4: Average order value and margin (V, M)

Get V from your invoices in Xero, QuickBooks or whatever you invoice from, excl. VAT. For M, use the gross margin your accountant or finance lead works with. If equipment hire or subcontractors are a big part of an order, margin tells you much more than revenue does.

Step 5: Time spent on stale enquiries (H × R)

Ask the team to note for two weeks how long they spend on enquiries that are already old: finding the thread, rewriting a half-finished quote, writing the "sorry for the late reply" email. Then double it to get a month. For R, use the loaded hourly cost of the person doing the work, not their billing rate.

Fill-in calculator template

Copy this into a spreadsheet. Fill in the right-hand column, then multiply.

Fill in both rows for L. If even the cautious figure is uncomfortable, you've found a real problem. If only the upper figure is, look closer before you spend money on it.

Break-even: what a fix may cost before it stops paying off

Any fix costs something: a new hire, a shared inbox rota, an AI tool, or simply the owner's evenings. To check whether it pays off, turn the formula around and ask how many extra won orders per month would cover the cost of the fix.

Orders needed to break even = monthly cost of the fix ÷ (V × M)
Enquiries you need to stop losing = orders needed ÷ W

Compare the second number with E × L, the enquiries you currently lose to delay. If you only need to save a small part of them, the fix carries little risk. If you would need to save nearly all of them, either the fix costs too much or delay isn't your main problem.

When you compare options, count the full monthly cost. For an AI tool, that means the subscription plus any language model usage you pay separately. Our article on estimating AI costs in advance shows how to keep those two apart. Current plans are on the pricing page, and there is a short answer on what an AI sales assistant costs a small business.

Common mistakes that distort the result

• Counting every lost enquiry as lost to delay. Some clients were only checking prices. Only group 1 belongs in L.
• Using revenue instead of margin. This makes the problem look bigger than it is, especially in rental and production, where a lot of each order goes on hire and crew costs.
• Ignoring the follow-up gap. Delay doesn't only happen at the first reply. A quote sent quickly and never followed up is lost the same way. If this happens to you, read how to stop forgetting quote follow-ups.
• Measuring once. L changes with the season and with who is on holiday. Do the count again each quarter.
• Fixing speed by lowering quality. A fast reply with the wrong price creates a new problem. The steps in speeding up proposals without losing control of prices help you avoid that.

If the slow part is the first reply itself, the five steps to replying faster and these email templates for common enquiry situations are a good start before you change any tools.

How BOTrento helps, and how to test it on your own data

BOTrento Chief of Staff is a managed process for enquiries, quotes and follow-ups. It doesn't replace your CRM or your accounting software. It watches the inbox and the data you upload and makes sure the next step doesn't get forgotten. Nothing is sent without a person's approval.

Here is what the 14-day free trial looks like if you want to check your own L instead of guessing it:

1. Connect or upload. Connect a mailbox via IMAP, or forward or import mail from Gmail, Google Workspace or Microsoft 365. You can add CRM or spreadsheet data as CSV/XLSX. The 14 days start only after your first successful data upload, and you have 7 days to get ready. Within 24 hours on working days, one of our team will contact you and help you connect your mailbox.
2. See what has already slipped. At the start you get a "Lost money" report. It looks back over past mail only for a mailbox connected via IMAP. It shows enquiries and quotes that were left without a next step, which gives you real data for group 1 and group 3.
3. Each working-day morning. A Today 1+3 overview, in the app and by email, shows the one most important item and three more to deal with that day.
4. Approve, don't write from scratch. BOTrento prepares draft replies, quotes and follow-ups in English, German, French or Czech. It works from the text of the email, not from attachments. You check each draft, change it if needed, and send it yourself.
5. Promises are tracked. If someone writes "I'll get back to you by Friday", BOTrento records it and reminds you.

AI usage is included in the plan with a monthly limit, so there are no surprise extra charges. You don't need a card or your own API key to try it. To see how the process works before you sign up, look at the process walkthrough or the page for equipment rental companies. Then start your 14-day free trial and run the calculator above with real figures.