Practical guide · Formats and pixels
To find out the pixels needed for a canvas format, calculate each side: centimeters RAM 2.54 × pixels per inch. The tables below give the dimensions of the face at 150, 200 and 300 ppp, excluding mounting reserves. They are used to size the file; they do not guarantee the sharpness of an original or the commercial availability of a format.
The dimensions below are calculation examples, not a list of guaranteed formats available for sale. The images are AI-generated illustrations.
1. The rule for converting centimeters into pixels
For each side, apply the formula: dimension in cm ÂX 2.54 × resolution in ppp. One inch measures 2.54 cm. PPPs, or PPI in English, indicate how many pixels in the file are distributed over one inch of printing.
Printers often use "DPI" in their instructions. For your photo, especially check the number of pixels actually available at the final size. The ink dots per inch of the machine correspond to another measurement.
150, 200 or 300 ppp: which column to consult?
300 ppp provides a store of detail for close observation when the original file allows it. Around 150 ppp, some canvases viewed remotely can remain convincing. 200 ppp constitutes an intermediate benchmark. Sharpness, subject, material and product requirements also matter.
To choose your resolution, consult our guide 150 or 300 DPI for printing on canvas?.
How to read tables: dimensions in pixels follow the order of dimensions in centimeters. For a horizontal canvas of 60 × 40 cm, invert the two numbers in the line 40 × 60 cm.
2. Pixels required for rectangular formats
The formats below cover several proportions. A photo with a 3:2 ratio is particularly suitable for 20 × 30, 40 × 60 or 60 × 90 cm; a photo with a 4:3 ratio corresponds to 30 × 40 or 60 × 80 cm. A photo with a 4:3 ratio corresponds to 30 × 40 or 60 × 80 cm. Check the framing before using the table.
| Format | 150 ppp | 200 ppp | 300 ppp |
|---|---|---|---|
| 20 × 30 cm | 1,182 × 1,772 | 1,575 × 2,363 | 2,363 × 3,544 |
| 25 × 35 cm | 1,477 × 2,067 | 1,969 × 2,756 | 2,953 × 4,134 |
| 30 × 40 cm | 1,772 × 2,363 | 2,363 × 3,150 | 3,544 × 4,725 |
| 30 × 45 cm | 1,772 × 2,658 | 2,363 × 3,544 | 3,544 × 5,315 |
| 40 × 50 cm | 2,363 × 2,953 | 3,150 × 3,938 | 4,725 × 5,906 |
| 40 × 60 cm | 2,363 × 3,544 | 3,150 × 4,725 | 4,725 × 7,087 |
| 50 × 70 cm | 2,953 × 4,134 | 3,938 × 5,512 | 5,906 × 8,268 |
| 50 × 75 cm | 2,953 × 4,430 | 3,938 × 5,906 | 5,906 × 8,859 |
| 60 × 80 cm | 3,544 × 4,725 | 4,725 × 6,300 | 7,087 × 9,449 |
| 60 × 90 cm | 3,544 × 5,315 | 4,725 × 7,087 | 7,087 × 10,630 |
| 70 × 100 cm | 4,134 × 5,906 | 5,512 × 7,875 | 8,268 × 11,812 |
| 80 × 120 cm | 4,725 × 7,087 | 6,300 × 9,449 | 9,449 × 14,174 |
| 100 × 150 cm | 5,906 × 8,859 | 7,875 × 11,812 | 11,812 × 17,717 |
Calculations for the visible side, excluding manufacturing margins; each value is rounded up to the next pixel in order to achieve at least the resolution indicated on the side concerned.
Example: a face of 30 × 40 cm at 200 ppp requires approximately 2,363 × 3,150 pixels. A larger file may be suitable, provided you maintain the correct ratio of proportions and sufficient quality.
3. Pixels needed for a square canvas
A square canvas uses as many pixels in width as in height. If your photo is rectangular, square cropping removes part of the image. Calculate the resolution with the cropped file.
| Format | 150 ppp | 200 ppp | 300 ppp |
|---|---|---|---|
| 20 × 20 cm | 1,182 × 1,182 | 1,575 × 1,575 | 2,363 × 2,363 |
| 30 × 30 cm | 1,772 × 1,772 | 2,363 × 2,363 | 3,544 × 3,544 |
| 40 × 40 cm | 2,363 × 2,363 | 3,150 × 3,150 | 4,725 × 4,725 |
| 50 × 50 cm | 2,953 × 2,953 | 3,938 × 3,938 | 5,906 × 5,906 |
| 60 × 60 cm | 3,544 × 3,544 | 4,725 × 4,725 | 7,087 × 7,087 |
| 80 × 80 cm | 4,725 × 4,725 | 6,300 × 6,300 | 9,449 × 9,449 |
| 100 × 100 cm | 5,906 × 5,906 | 7,875 × 7,875 | 11,812 × 11,812 |
A photograph of 6000 × 4000 pixels can provide a maximum of one square of 4000 × 4000 pixels without adding pixels. This square represents approximately 203 ppp over 50 × 50 cm and 169 ppp over 60 × 60 cm.
Practical advice: choose square framing before final edits. Check that the subject retains space around it and that no important details disappear.
4. Pixels needed for a panoramic canvas
A panorama requires a lot of pixels on the long side. The following examples are at the 3:1 ratio. They are suitable for an image composed for this proportion or for carefully prepared cropping.
| Format | 150 ppp | 200 ppp | 300 ppp |
|---|---|---|---|
| 60 × 20 cm | 3,544 × 1,182 | 4,725 × 1,575 | 7,087 × 2,363 |
| 90 × 30 cm | 5,315 × 1,772 | 7,087 × 2,363 | 10,630 × 3,544 |
| 120 × 40 cm | 7,087 × 2,363 | 9,449 × 3,150 | 14,174 × 4,725 |
| 150 × 50 cm | 8,859 × 2,953 | 11,812 × 3,938 | 17,717 × 5,906 |
A photo of 6,000 × 4,000 pixels cropped in 3:1 only retains a maximum of 6,000 × 2,000 pixels. On a 90 × 30 cm side, it gives approximately 169 ppp, before taking into account the margins.
Mistake to avoid: stretching a photograph to fill a panorama distorts faces and objects. Crop, adapt the presentation according to the options offered or choose a larger image.
5. How to check if your photo contains enough pixels?
Open the information in the original file and locate its dimensions, for example 4032 × 3024 pixels. Megabyte weight is not enough: it varies with compression, format and image content.
Example with a photo of 4,032 × 3,024 pixels
This file with a 4:3 ratio corresponds to a face of 40 × 30 cm. The effective resolution is 4032 Μ (40 × 2.54), or approximately 256 ppp. On 60 × 45 cm, it drops to approximately 171 ppp. In both cases, the height gives the same value.
What format to get without adding pixels?
The opposite formula is: pixels ÂX resolution × 2.54 = dimension in cm. At 300 ppp, a file of 4032 × 3024 pixels corresponds to approximately 34.1 × 25.6 cm. At 200 ppp, it corresponds to approximately 51.2 × 38.4 cm. At 200 ppp, it corresponds to approximately 51.2 × 38.4 cm. At 200 ppp, it corresponds to approximately 51.2 × 38.4 cm. These values are calculated sizes, not guaranteed commercial formats.
Then check the sharpness of the eyes, contours and textures. A blurry image remains blurry even if it has a lot of pixels. For a large order, manufacturer validation or proofing the intended media can help.
6. Provide cropping and chassis margins
The tables in this article describe the visible side. For a canvas mounted on a frame, the file may need to cover the sides and margins necessary for assembly. The depth of the frame and the finish chosen determine the preparation.
An example of calculation with margins
Suppose that a template requires a complete file of 46 × 66 cm for a face of 40 × 60 cm. At 200 ppp, the complete file must measure at least 3,623 × 5,198 pixels. This example illustrates the formula; it does not constitute a standard margin to be applied to all canvases.
With mirrored or plain edges, the service provider can prepare the sides from the face. With an extended image, part of the photograph may leave the main surface. Check who is preparing the margins and what the preview shows.
Changing "72 DPI" to "300 DPI" does not create details
Without resampling, changing the resolution value does not change the number of pixels. A software enlargement adds more by calculation; you have to check the result and any artificial details. Reducing the format or finding a better original may be preferable.
Before shipping: check the file after cropping, the full format of the template, the requested color profile and the export quality. Find the other steps in our guide to taking a successful photo on canvas.
Calculate two distinct physical dimensions
First write the visible width and height, then the necessary reserves on each side. If the reserves are different, add them separately: total width = face + left reserve + right reserve; total height = face + high reserve + low reserve.
Then convert each dimension with the formula cm RAM 2.54 × ppp. Pixel values must be related to the same physical size and density. The total number of pixels in a document with borders alone does not describe the detail available in the visible image.
Read a table with reservations: fictitious examples
| Visible face (width × height) | Document with 5 cm per side | Document at 150 ppp | Document at 300 ppp |
|---|---|---|---|
| 40 × 30 cm | 50 × 40 cm | 2,953 × 2,363 px | 5,906 × 4,725 px |
| 60 × 40 cm | 70 × 50 cm | 4,134 × 2,953 px | 8,268 × 5,906 px |
| 80 × 60 cm | 90 × 70 cm | 5,315 × 4,134 px | 10,630 × 8,268 px |
These examples are calculated with a fictitious reserve of 5 cm on each of the four sides and a rounding to the upper pixel. They do not guarantee the sizes offered by Alpha, nor the reserve necessary for a particular chassis. The actual instructions may be different.
A plain margin can be created in the document without adding detail to the photo. A folded, mirrored or extended image area must instead be prepared according to the validated rendering and framing. Do not infer from this table that any photo must contain as much photographic detail as the complete document.
Avoid double adding margin in the order
Reread the template and the chosen presentation: is the seller preparing the edges or waiting for a file already composed? Does the size indicate the total fabric or the final side? An included reserve should not be added automatically again.
In the Alpha selection of controlled rolled canvas for this project, the size indicated includes the announced margin. Have its application confirmed to your work and local editing. For a personal file, keep an original version and an identified working document with face, margins and density, then have everything validated before sending.
Switch from the pixel table to your command
The dimensions to compare are those of the file after cropping and those of the desired visible side. Also note the reservations necessary for edges and editing: they are not confused with the face of the image. The tables in the guide give definition marks; the template confirmed for the product determines the final file.
To view two presentations on the same work, examine The Great Wave on canvas on frame and The Great Wave on unframed paper. These catalog examples are not commands for your photo: they show constructs to distinguish before preparing the file.
For a personal image, contact Alpha Reproduction with the original file, its width and height in pixels, the desired framing, the visible dimension and the presentation. Have the proposed format, template and export instructions confirmed. A high weight in megabytes does not replace checking sharpness and useful pixels.
Calculate centimeters from file · Evaluate the limitations of a low resolution file.
Compare Alpha Reproduction media · contact Alpha Reproduction
Our offer: link the file to canvas format
The support and editing do not compensate for an insufficient file. For our canvas printing, choose the size and presentation before calculating the useful resolution; also check the framing that will remain on the facade. The examples in the catalog show the finishes, without validating a personal photograph.
Our prints use a finely textured 400 g/m² artistic canvas. The rolled version is without frame or frame. The canvas on frame is stretched by hand over 38 mm wood; the American box adds a wooden frame with a space of 5 mm around the canvas. The dimensions, edges, finishes and prices offered can be consulted depending on the work and the country of delivery.
Alpha Reproduction · Rolled printed canvas · care and preparation of the file
Visible pixel tables should not be read as complete rolled canvas templates. Only add the areas actually requested for edges and editing, checking if they are already included in the announced format.
Prepare the complete file and its validation
To check another example: pixel to centimeter calculator for canvas. Always distinguish face and document before entering the dimensions.
Frequently asked questions
How many pixels do you need for a 30 × 40 cm canvas?
For the visible side, at least 1,772 × 2,363 pixels at 150 ppp, 2,363 × 3,150 pixels at 200 ppp or 3,544 × 4,725 pixels at 300 ppp, with upper rounding. Add the margins only according to the manufacturer's instructions.
How many pixels do you need for a 60 × 90 cm canvas?
For the visible side, 3,544 × 5,315 pixels at 150 ppp, 4,725 × 7,087 pixels at 200 ppp or 7,087 × 10,630 pixels at 300 ppp, with higher rounding. The quality of the original remains to be verified.
Is a 12 megapixel photo enough?
It depends on the format, proportions and cropping. A 4000 × 3000 pixel photo has 12 million pixels, but you have to compare each side to the final format rather than relying on the number of megapixels alone.
Do you need exactly the dimensions shown in the table?
No. A larger file may be suitable. The tables are used to understand the needs for the visible side; the manufacturer's template gives the exact dimensions to be provided.
Why does cropping change the resolution?
It removes pixels. If you print the remaining file to the same size, you distribute fewer pixels on each inch of canvas. So calculate the resolution after cropping.
Is a heavy image necessarily suitable for a large canvas?
No. The size of the file does not guarantee its sharpness or its pixel dimensions. A poorly compressed but blurry image can be heavy and give a poor result.
Why do some tables give a pixel difference?
Conversions in centimeters often produce fractions of a pixel. This guide rounds to the top pixel; other tables round as close as possible. Follow the exact dimensions of the manufacturing template.
The right format starts with the right file
Note the dimensions of your photo, choose its framing, then compare the available pixels to the desired canvas format. Then check the product margins and the sharpness of the original. This method allows you to choose a consistent format and prepare a file suitable for printing.
Technical sources: Adobe - size, resolution and resampling ; Prodigi - image requirements ; Prodigi - preparation of margins and templates. Table calculations are made from 1 inch = 2.54 cm.
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