How long it runswhen you say it out loud.
Word count means nothing for video, runtime is everything, because the slot is fixed. Paste your script and see exactly how long it takes to deliver at your chosen pace, or flip it around: give a target duration and get the word budget to write to. Then check whether it fits a 6, 15, 30, or 60 second ad slot before you ever step up to the mic.
Your script
Runtime
Runtime
0:20
Seconds
20s
Words
49
At pace
150 wpm
Your move
A script that fits the slot is the start. A script that sells is the craft.
49 words ≈ 0:20 at 150 wpm.
Hitting the time is the easy part, making 75 words actually move someone to buy is where most ads fail. That's what I write: short form scripts that hook, hold, and convert inside the slot. Send me the brief and I'll show you, free, how I'd write it.
Plain English
Video doesn't count words. It counts seconds.
The bridge between a written script and its runtime is speaking pace, measured in words per minute. Read at a conversational 150 words per minute, a 30 second ad has room for about 75 words, and not one more. Writers who draft to a word count instead of a time budget end up with scripts that either rush the voiceover into an unintelligible blur or run long and blow the slot. Timing the script first saves the expensive surprise in the recording booth.
Pace is the variable that matters most, and it's not one number. A luxury brand voiceover crawls at 110 words a minute for gravitas; a hype trailer or fast TikTok ad sprints past 180; legal disclaimers hit auctioneer speed. The same script can run 25 seconds or 40 depending on delivery. That's why this tool lets you pick the pace, slow narration to very fast, rather than pretending there's a universal speaking speed.
Use it both directions. Paste a finished script to get its runtime and see which standard ad slot it fits inside, with seconds to spare or over. Or start from the slot, '15 seconds', and get the exact word budget, so you write to the time from the first draft. Either way you walk into production knowing the script fits, instead of finding out when the timer runs out.
The formula
Runtime (seconds) = (word count ÷ words per minute) × 60
A 120 word script read at a conversational 150 wpm runs 120 ÷ 150 × 60 = 48 seconds, too long for a 30 second spot, a clean fit for a 60. Working backwards, a 30 second slot at the same pace gives a budget of 75 words. Write to that and the voiceover lands on time, every take.
Words that fit each slot
Approximate word budgets for the standard ad and video slots at a conversational 150 wpm. Slow the pace and the budget shrinks; speed up and it grows, adjust with the pace selector:
| Slot | Words (~150 wpm) | Use |
|---|---|---|
| 6s bumper | ~15 words | One idea, one CTA |
| 15s spot | ~37 words | Single hook + offer |
| 30s spot | ~75 words | Standard ad |
| 60s spot | ~150 words | Story + proof + CTA |
Source: Voiceover & speaking-pace standards · Standard
Your script doesn't fit. What to do.
Runs a few seconds over the slot.
Cut, don't speed up. Trim filler words, combine sentences, and drop the least important point. A script that fits at a natural pace always beats one rushed to fit.
Way over the slot.
It's the wrong slot or the wrong cut. Either move up a length or restructure around a single core message, long form scripts crammed into short ads never work.
Comfortably under the slot.
Good, leave breathing room for pauses, music, and a clean end card. Filling every second wall to wall makes an ad feel frantic.
Pace set faster than the brand sounds.
Don't solve a length problem by speeding up the read past what the brand should sound like. Match the pace to the tone, then cut words to fit.
Lots of numbers, names, or tongue twisters.
Hard to say copy reads slower than its word count suggests. Build in extra time, or simplify the wording for the voice talent.
How to write to time
01Write to the slot, not the page
Start from the duration and its word budget. Drafting to a time from the first line is far easier than hacking a long script down later.
02Front load the hook
In a short spot the first 1 to 3 seconds decide whether anyone keeps watching. Spend your earliest, most precious words on the hook.
03Leave room to breathe
Aim for ~90% of the slot, not 100%. Pauses, music stings, and a clean CTA need seconds too, a packed read feels cheap and rushed.
04Match pace to tone
Pick the pace that fits the brand first, then fit the words to it. Speeding up to cram in copy undoes the feeling you're trying to create.
05Read it aloud, timed
The estimate is close, but your delivery is the truth. Read it on a timer, tricky words and natural pauses always add seconds.
06Cut adjectives before ideas
When you're over, trim modifiers and filler first. Protect the core message and the call to action; everything else is negotiable.
The vocabulary
- Words per minute (wpm)
- Speaking pace. Conversational delivery is ~150 wpm; narration is slower, hype is faster.
- Runtime
- How long a script takes to deliver out loud, the number that matters for video and audio, not word count.
- Word budget
- The maximum words that fit a target duration at a chosen pace. Write to it from the first draft.
- Ad slot
- A standard fixed duration for an ad, 6, 15, 30, or 60 seconds, that your script must fit inside.
- Bumper
- A very short (typically 6 second) non skippable video ad. Room for roughly 15 words, one tight idea.
Script timing questions, straight answers
Divide the word count by your speaking pace in words per minute, then multiply by 60 for seconds. At a conversational 150 wpm, 150 words takes about a minute. Narration runs slower (~110 wpm) and energetic delivery faster (~180 wpm), so the pace you pick changes the answer significantly, this calculator lets you set it.
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.