AI Video Credits Explained: Why Clip Costs Vary So Much

Short answer: with AI video credits explained in one line, most generators charge a credit rate per second of video, and that rate changes with the model, the audio setting and the resolution. Multiply the rate by the clip length and you have the cost of one attempt. On Runway's model list, read on September 27, 2026, Gen-4 Video Turbo was listed at 5 credits per second and Gen-4.5 at 12, so the same 10 second idea costs 50 credits on one and 120 on the other. Then multiply by the number of attempts you actually make.

That is the whole system. The confusion comes from the fact that plan pages advertise a credit total, while the cost of a clip depends on four settings you choose each time you press generate.

The formula behind every credit charge

Almost every credit-based video tool comes down to this:

Cost of one attempt = rate for your settings × seconds generated

Real cost of one usable clip = cost of one attempt × number of attempts

The first line is set by the vendor. The second line is set by you, and it is usually the bigger surprise.

Runway's model and pricing page on Runway Academy, read on September 27, 2026, lists costs as rates, such as "12/sec," rather than as prices per clip. That is the key detail most people miss: a monthly credit total on a plan page is not telling you how many videos you get. It is telling you how many seconds you can afford at whatever rate you choose.

The four settings that change the rate

1. The model

This is the biggest lever. Runway's list showed, on September 27, 2026:

Same platform, same account, and the most expensive model on that list costs more than five times the cheapest per second. A clip that "costs 40" and one that "costs 300" can both be completely normal. They were just made with different models or lengths.

2. The clip length

Credits on these lists are charged per second generated, not per second you keep. A 10 second generation costs twice a 5 second one on the same model, even if you only use three seconds of it. Available lengths also vary by model, so the shortest option on a premium model may still cost more than the longest on a budget one.

3. Audio

Models that can generate sound often charge more when you turn it on. On the same Runway page:

For Veo 3.1 on that list, audio doubles the rate. If you plan to replace the sound in your editor anyway, generating with audio can mean paying for something you delete.

4. Resolution

Higher resolution usually costs more per second. Runway's developer API pricing page, read on September 27, 2026, listed Seedance 2 at 40 credits per second for 1080p and 150 credits per second for 4K. That page also listed an API credit price of $0.01, which applies to developer API use, so check the plan page for the app you actually use. On the Runway Academy page, several Alibaba models were also priced separately at 480p, 720p and 1080p.

Why two "identical" clips cost different amounts

Put the four settings together and the gap explains itself. Using the rates above, from the pages read on September 27, 2026:

These are arithmetic on the vendor's listed rates, not prices we measured, and the lengths are examples: check which durations each model actually offers before you plan. The point is the spread. Nothing about the prompt changed, only the settings.

The multiplier nobody lists: attempts

The rates above are for one attempt. What you pay for a usable clip depends on how many tries it takes, and no vendor page can tell you that number, because it depends on your prompt, your subject and how picky you are.

A simple way to see why this matters: if a clip costs 120 credits per attempt and it takes you three attempts to get one you keep, that clip really cost 360 credits. If you budgeted for 120, you will run out three times faster than you planned.

That is why a credit total on a plan page is best read as "seconds of attempts," not "seconds of finished video." We have not measured typical attempt counts for any tool, and we would be wary of any page that gives you one number for everyone. Track your own for a week and you will know yours.

How to estimate before you generate

Before you start a project, do this once:

1. Write down the finished length you need. For example, 30 seconds of AI footage in a video.
2. Choose the model and settings, then look up the current per-second rate on the vendor's own page.
3. Multiply rate by seconds to get the cost of one pass through all the clips.
4. Multiply by your own attempt count. If you do not know it yet, assume more than one and check after the first few clips.
5. Compare with what is left in your balance. If it does not fit, change a setting before you start, not halfway through.

Doing this for one project is usually enough to change how you work, because you see which setting is costing you most.

Ways to spend fewer credits without lowering the final result

These follow directly from the rate structure, and they do not depend on any particular tool:

• Draft on a cheaper model, finish on a better one. Use a low rate model to test framing and motion, then spend premium credits only on prompts that already work. The result will not be identical across models, but you will waste fewer expensive attempts.
• Generate the shortest clip that covers the shot. If you need four seconds, a 10 second generation doubles the cost of the attempt for footage you will cut.
• Turn off audio if you will replace it. On models that price audio separately, this can cut the rate substantially.
• Draft at a lower resolution where the model allows it, then generate the final version at the resolution you will publish.
• Write the full prompt before the first run. Adding one detail per attempt turns one generation into five.

Sometimes the cheapest option is not generating at all. For generic shots like city skylines or hands on a keyboard, licensed footage may do the job for less. We compare the two in AI video vs stock footage.

Things to check on any credit plan

Credit rules differ between tools and change often. Before you buy, look on the vendor's own pages for:

• The per-second rate for each model you plan to use, not just the plan's credit total.
• Whether audio, resolution or special output formats cost extra.
• What happens to unused credits at the end of the month: whether they reset, roll over or expire.
• Whether a failed or cancelled generation is charged.
• Whether credits bought in one place (an app plan, a developer API) can be used in another.

Write down the date you checked. A rate you read three months ago may not be the rate today. If you use more than one tool, a simple monthly check of what you actually used is worth more than any plan comparison, and our guide to AI tools that are actually worth your time covers how to decide what stays.

What this article does not do

It does not rank tools by value, and it does not tell you what a finished minute costs, because that depends on your own attempt rate, which only you can measure. All rates here are the vendor's own listed rates on the date shown. They will change.

FAQ

Why did one AI video cost so many more credits than another?

Usually because of the model, the clip length, audio or resolution. On Runway's list, read September 27, 2026, rates ranged from 5 credits per second for Gen-4 Video Turbo to 28 for Aleph 2.0, and Veo 3.1 doubled from 20 to 40 per second with audio on.

Are AI video credits charged per clip or per second?

On Runway, the listed costs are per second of generated video. Multiply the rate by the clip length to get the cost of one generation. Other tools may count differently, so check their own pricing page.

Do I pay credits for clips I do not keep?

A per-second rate is charged on what is generated, and a generation you discard still had to be generated. That is why the real cost of a usable clip is the cost of one attempt multiplied by the number of attempts. Check your tool's help pages for how it treats failed generations.

How can I make my credits last longer?

Test prompts on a cheaper model, generate only the length you need, turn off audio you will replace, and write the full prompt before the first run.

Do unused credits roll over?

It depends on the tool and plan. Check the vendor's own pricing or help page before buying, and note the date you checked.