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Free tool · Ebook File Size Calculator

Ebook File Size Calculator that shows how big your ebook will be and what delivery costs

The ebook file size calculator estimates the size of your ebook from the word count, the number and average size of your images, embedded fonts and the cover, and shows the delivery charge that applies on a high-royalty plan, both in dollars and as a share of your price. It runs in your browser and is free for self-published authors, especially those with illustrated or image-heavy books.

Use the free tool

The ebook file size calculator is free to use, with no account and nothing uploaded.

  • Size from words and images
  • Delivery charge
  • Plain advice

Key facts

  • FreeNo cost, no account and no usage limit on the ebook file size calculator
  • In your browserNothing that you type or paste into the ebook file size calculator is uploaded
  • SecondsTypical time from opening the ebook file size calculator to a result
Free tool

Ebook file size calculator

Estimate the size of your ebook file from the word count and the images, and see the delivery charge that applies on a high-royalty plan.

The ebook file size calculator needs JavaScript, and it works in your browser without sending anything that you enter to a server.

Overview

What the ebook file size calculator does and why it helps

An ebook file is mostly text and images, and the text is the smaller part. A novel of 80,000 words takes only a few hundred kilobytes once it is compressed inside the file. The images, the fonts and the cover make up nearly everything else, and a book with a dozen photographs can run to several megabytes. File size matters for two reasons. Large files load slowly on older devices and in low-bandwidth places, and some retailers charge a delivery fee on higher-royalty plans that is based on the size of the file.

The calculator estimates the size from what you tell it. Enter the word count, the number of images, the average size of an image in kilobytes, the size of any embedded fonts and the size of the cover, and the tool estimates the text at about six characters per word with typical compression, adds the images, fonts, cover and a small amount for the structure, and gives the total in kilobytes and megabytes. It then multiplies the megabytes by the delivery charge per megabyte that you enter, which gives the charge per copy and the charge as a share of the list price.

The result shows where the weight is and what it costs. If the images are the main part, you can compress them or reduce their dimensions, because an ebook screen does not need a print-resolution photograph. Embedded fonts can be removed or limited, since most reading apps let the reader choose a font. Check your platform's current rules on delivery charges, because they differ between plans and change, and treat the figure as an estimate until you have the real file size from your formatter.

The ebook file size calculator estimates the size of your ebook from word count and images, which matters for delivery fees on some stores. This is a free ebook file size calculator, built for authors who want a clear answer without buying software. You can use the ebook file size calculator online in any modern browser, with nothing to install. We built it as an ebook file size calculator for authors, with book-specific defaults. Indie writers can rely on it as an ebook file size calculator for self-published books. It doubles as an ebook file size calculator for KDP, because the figures it uses match Amazon's rules. There is no account to create, so this ebook file size calculator no sign up page is ready the moment it loads. If you are hunting for the best ebook file size calculator, judge it by whether it explains its numbers, as this one does.

How to use it

How to use the ebook file size calculator, step by step

01

Enter your word count

Type the word count of your book. Text is a small part of an ebook's size, but the tool needs it for a baseline.

02

Enter the number of images

Type how many images the book contains. Images are usually the largest part of an ebook's size, so an accurate count matters.

03

Enter the average image size

Type the typical size of one image in kilobytes. Check your own files, since an uncompressed photograph can be several megabytes. If a value looks wrong, change it and read the result again; the ebook file size calculator never stores or uploads what you enter.

04

Add embedded fonts and the cover

Enter the size of any embedded fonts and of the cover image. Fonts and covers are small but not zero. The ebook file size calculator updates as you type, so you can correct a value and see the result straight away.

05

Read the estimated file size

The tool adds the parts and shows the size in megabytes. Compare it with the limits of the stores you plan to use.

06

Read the delivery charge

On a high-royalty plan the platform deducts a charge per megabyte. The tool shows it in dollars and as a share of your price, so that you can see its effect.

How the ebook file size calculator works

Text is small, images are large

You enter your word count, the number of images, the average image size, any embedded fonts, the cover size, the delivery charge per megabyte and the price. The tool estimates the compressed text size from the word count, adds the images, fonts and cover and gives the total in kilobytes and megabytes.

It then multiplies the megabytes by the delivery charge, shows the charge per copy and as a share of the price, and tells you whether the file is comfortable or large. A novel with no images is usually a few hundred kilobytes, and a book with many photos can run into tens of megabytes.

To reduce size, compress images to the size they are shown at, use JPEG for photographs and PNG only where needed, remove unused fonts and avoid very large cover images. The estimate is a guide, and the file in your preview or your validator tells you the true size.

  • Text, images and fonts counted separately
  • The delivery charge per copy
  • Advice on large files
Method

How the ebook file size calculator works out its answer

Text size

The tool assumes about six characters per word, compresses the text with a typical ratio of about 35 percent and converts the result to kilobytes.

Images, fonts and cover

The number of images is multiplied by their average size, and the fonts and the cover are added, along with a small allowance of about 30 kilobytes for the book's structure.

The total

The sum is shown in kilobytes and in megabytes, with the text and image parts shown separately.

Delivery charge

The megabytes are multiplied by your delivery charge per megabyte, which gives the charge per copy and its share of the list price.

Worked examples

Ebook File Size Calculator: worked examples

A novel with no images

The file is under 1 megabyte and the delivery charge is almost nothing. The author takes the higher royalty plan. The figures are illustrations, and your own text or settings will give different numbers in the ebook file size calculator.

A photo book with 80 images

At 1 megabyte per image the file is about 80 megabytes, and the delivery charge is a large share of the price. The author compresses the images and recalculates in this ebook file optimisation order.

A cookbook with 40 images

The tool shows a moderate file size and a small charge. The author keeps the images at a good size. The figures are illustrations, and your own text or settings will give different numbers in the ebook file size calculator.

Key terms

Key terms to know when you use the ebook file size calculator

File size

The size of the ebook file in megabytes. It is the sum of text, images, fonts and the cover.

Delivery charge

A fee per megabyte deducted from royalties on some plans. The ebook file size calculator uses the term in exactly this sense throughout its results and notes.

Compression

Reducing the size of a file, often by lowering image quality slightly. The ebook file size calculator uses the term in exactly this sense throughout its results and notes.

Kilobyte

A thousand bytes, a unit often used for image sizes. The ebook file size calculator uses the term in exactly this sense throughout its results and notes.

Megabyte

A thousand kilobytes, the unit used for delivery charges. The ebook file size calculator uses the term in exactly this sense throughout its results and notes.

Royalty plan

A set of terms that decides the share of the price the author earns.

Use cases

Where authors use the ebook file size calculator

Estimating the cost of delivery on an illustrated ebook

See how much the delivery charge reduces the royalty on a large file. For a photo-heavy book it can be a large share. The ebook file size calculator runs in your browser, so you can try it with real figures straight away and without an account.

Deciding how far to compress images

Compare the size and delivery charge for different image sizes, and choose the balance between sharpness and cost. It takes a minute with the ebook file size calculator and can save hours of rework at a later, more expensive stage.

Choosing between royalty plans

See whether a lower royalty rate with no delivery charge beats a higher one with a charge for your file size. You can share the result of the ebook file size calculator with an editor, designer or formatter who needs the same numbers.

Common mistakes

Mistakes the ebook file size calculator helps you avoid

Using uncompressed images

A raw photograph can be many megabytes. Compress images to what the screen needs, usually about 1600 pixels on the long side. The ebook file size calculator can only work with what you give it, so careful input is the best protection against this.

Forgetting the cover and fonts

They are small but they add up, and the tool counts them. Include them. Checking for this with the ebook file size calculator costs almost nothing, and correcting it later can mean rework.

Ignoring the store's maximum

Platforms limit file size. Check the limit before you upload. The ebook file size calculator will not catch this for you, so keep it in mind when you read the result.

Tips

Getting the most from the ebook file size calculator

01

Compress before you count

Resize and compress images first, and then enter the real average size. The result will be more useful. The ebook file size calculator is free and instant, so it is worth running again whenever your book changes.

02

Test the plan with a realistic price

The delivery charge matters more at a low price. Enter your real price. Make the ebook file size calculator a routine step on every project, so that results stay consistent from book to book.

03

Consider fixed layout carefully

Fixed-layout files are larger. Compare the cost before you choose. A few minutes with the ebook file size calculator now saves time across the whole manuscript.

Limits

How far to trust the ebook file size calculator

An estimate

Real file sizes depend on the compression and the structure of the file. Treat the ebook file size calculator as a quick, free check, and confirm anything important with the platform or printer you will use.

Rates change

Delivery charges and royalty plans are set by platforms and may change. The ebook file size calculator gives guidance, not a guarantee, so use it alongside your own judgement and, where it matters, a specialist.

No quality check

The tool counts size, not whether images look good. For your ebook file optimisation, it runs in your browser with the figures you enter, so its answers are only as accurate as those figures.

Need it done for you?

When the ebook file size calculator is not enough

The calculator shows the weight of your ebook. These services build the file to be light and sharp, and test it on real devices.

Before and after

Before and after using the ebook file size calculator

The same illustrated ebook, first built with print-size images and then built with images sized for the screen.

  1. 1Photographs at print resolution
  2. 2A large file that loads slowly
  3. 3A delivery charge that cut into the royalty
  1. 1Images sized and compressed for screens
  2. 2A file that loads quickly
  3. 3A delivery charge that is a small share of the price
  • 3problems found in the first review
  • 3fixes checked in the final review
  • 1named specialist owning every fix
  • Fixedprice confirmed in the calculator before you order
01

A lighter file

Images are resized for the screen, so the file downloads and opens quickly on any device.

02

A bigger royalty

A smaller file means a smaller delivery charge, so more of each sale reaches you.

03

Better reading

The book opens quickly on older devices and slow connections, so more readers can enjoy it.

Client reviews

What authors say about our ebook file optimisation service

Verified reviews from authors who asked a specialist to handle the ebook file optimisation after using the ebook file size calculator.

The publishing readiness review identified four issues in my manuscript that would have caused rejection. Each was clearly explained and quickly resolved. My book launched without any technical complications.

Sigrid LindqvistSelf-Help Author Publishing Support Client, FinlandVerified client

The formatting error fix service saved my launch. My original formatter had made margin errors causing repeated rejection. Book Formatting Experts identified and fixed every issue within 48 hours. My launch was back on schedule.

Ifeoma ChukwuThriller Author Publishing Support Client, NigeriaVerified client

Getting historical fiction placed in the right categories on Amazon and IngramSpark required strategic metadata. The team understood the genre classification and the book reached the right readers from the first week.

Nkechi AdeyemiHistorical Fiction Publishing Support Client, NigeriaVerified client

As a first-time author, the technical side of self-publishing was genuinely daunting. The consultation covered every decision — platform choice, pricing strategy, metadata, and distribution. I launched with genuine confidence.

Obi NwosuDebut Nonfiction Author, NigeriaVerified client

Good support throughout the KDP upload process. The metadata setup and category selection were explained clearly. One pricing setting needed adjustment after initial setup but it was corrected quickly.

Aleksei PetrovFantasy Author Publishing Support Client, RussiaVerified client

My cookbook needed to be set up across multiple platforms simultaneously. The publishing support team handled every submission — KDP, IngramSpark, and Apple Books — with different requirements for each. Flawlessly executed.

Cecile FontaineCookbook Author Publishing Support Client, FranceVerified client

My YA novel needed to reach both English-language and Japanese readers. The multi-region distribution setup was handled correctly across all required platforms. International sales have exceeded my expectations.

Yuki WatanabeYoung Adult Author Publishing Support Client, JapanVerified client

My KDP file was rejected with a technical error message I could not understand. Book Formatting Experts diagnosed the problem immediately — a bleed issue on three pages — and corrected it the same day. Approved first time.

Taiwo AdeyemiRomance Author Publishing Support Client, NigeriaVerified client

Navigating IngramSpark's requirements for the first time felt overwhelming. The upload assistance handled everything — metadata, pricing setup, distribution channels. My children's book reached bookstores within two weeks.

Samuel OkonkwoChildren's Author Publishing Support Client, GhanaVerified client
More free tools

More free tools to use with the ebook file size calculator

Each of these tools is free, runs in your browser and works well alongside the ebook file size calculator.

Image DPI Checker

Free image dpi checker that works in your browser, plus a done-for-you image resolution check service on this ebook file optimisation project.

Open the tool →
FAQ

Ebook File Size Calculator: questions answered

These are the questions authors ask most about the ebook file size calculator, including accuracy, privacy and what to do next. If your question about the ebook file optimisation is missing, request a quote and a specialist will reply.

What is an ebook file size calculator?

It is a tool that estimates the size of an ebook from its word count, images, fonts and cover, and shows the delivery charge that may apply.

How big is a typical ebook?

A text-only novel is usually well under one megabyte, and an illustrated book can be several megabytes or more.

How does the delivery charge hit a large ebook?

Some retailers deduct a fee based on file size on higher-royalty plans, so a heavy illustrated file can lose a real share of each sale.

How can I reduce my ebook file size?

Resize images to screen dimensions, compress them, use JPG for photographs, and avoid embedding fonts you do not need.

What image size is best for an ebook?

Most readers do not need more than about 1,000 to 1,600 pixels in width, and smaller for small images.

Do embedded fonts matter?

They add weight, and many reading apps let readers choose their own font, so embed only when it matters.

How is text size estimated?

The tool uses about six characters per word and a typical compression ratio, which is close for most books.

Does the cover count?

Yes. The cover image is part of the file, so keep it a reasonable size.

Will the real file size match the estimate?

It will be close for most books, and your formatter can tell you the exact size.

Does the delivery charge apply on every plan?

No. It applies on certain royalty plans, and rates change, so check your platform's current terms.

Does the ebook file size calculator keep anything that I enter?

No. The ebook file size calculator works in your browser, so what you enter stays on your device and is never saved.

Is the ebook file size calculator free?

Yes, the file size calculator costs nothing, needs no account and puts no limit on the estimates you run.

How does an ebook file size calculator work?

It adds an estimate for the text to the total size of your images.

How to use an ebook file size calculator?

Enter word count and image sizes and read the estimated file size.

Is there an ebook file size calculator with examples?

Yes. The page includes a worked example so you can compare it with your own numbers or text. Compare with and without images.

What is the ebook file size calculator formula?

File size is roughly text size plus the total size of each image.

Can I use a ebook file size calculator spreadsheet instead?

You can, and a ebook file size calculator spreadsheet works if you are happy to maintain the formulas yourself. This page does the maths for you and shows the working, so there is nothing to copy or update.

Work with a specialist

Turn what you learn from the ebook file size calculator into a finished book

The ebook file size calculator costs nothing, and so does asking what a specialist would do with your book. When the ebook file size calculator has done its part and you want finished files, a fixed price and one named person who owns the job, we are ready to start.