# Blender Precise Measurement

If Blender had precise measurements, the world would change. However, there is a limitation in decimal places, allowing only 5 decimal places, and rounding off when the limit is exceeded.

For instance, suppose you have a pencil with a length of 5.111115 inches, and you want to model and copy its length precisely. When you paste it in Blender, it becomes 5.11111, losing precision.

Please note that the viewport measurement values in Blender might be confusing, but they don’t affect the actual measurements.

For example:

When you enter 1.116113 with 6 decimal places,
Blender’s actual value becomes 1.11611 with 5 decimal places,
The viewport value shows as 1.12 with 2 decimal places due to rounding off.

Again, When you enter 1.116113, Blender’s limitation in decimal places causes the official and actual value to become 1.11611 (where the 3 goes? It becomes 0). However, in the viewport, it appears as 1.12 because the viewport shows only 2 decimal places and rounds off the value but it’s still 1.11611

I just sharing my thoughts here and i hope blender have freely decimal places like when you enter 5 decimal then it will automatically use 5 decimal and if it’s 6 then 6 and so on…

I’d like to know in real, practical terms why you need a 6th decimal place.

I’ve rebuilt car engines, and dealt with meeting a tolerance of .001 inches / .0254 mm. That’s only 4 decimal places, with no rounding needed.

10,000ths of an inch still needs only 5 places. Why do you actually need 1/millionth of an inch accuracy?

(Keeping in mind the goal of blender, which is not designing an F1 car.)

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also, if there is some reason you need to have measurements that small (perhaps you’re modelling atomic structures) you can change the unit scale that blender works in. See Scene Properties > Units > Unit Scale (and it’s tooltip)

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It’s about the general problem of implementation floating point numbers and there accuracy…

For example, the decimal numbers 0.1 and 0.01 cannot be represented exactly as binary floating-point numbers.

And for example you pencil… in hand made metal work you measure to to 1/100. with machine made ones maybe to the 1/1000… with wood… someone would be almost crazy to measure to 1/10…
…and pencils tend to shrink every time i use them…

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Why? And how? It doesn’t seem to me anything would change.

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thankyou sm for the info! I’m studying threaded for a few weeks now (mechs) for my personal project, exploring specs & blueprints and they’re using 2 - more than 6 decimal places, especially in tolerance and some pitch.
I’ve been thinking about it yesterday but yea before I open this pc today I just decided to use 6 decimals round off to continue and getting that info I started thinking that 4 decimals below would be more than enough!

sorry for my English

yea I tried that, it’s a little bit confusing but maybe I’ll experiment more with that

it’s a phrase that the speaker believes would be different if we have that.
example:
super users want to make complex things using complex tools but don’t have a complex tool to make but other software have, so you need other software that has complex tools you need but the condition will take your time. so if can achieve it on the software you used will be easier

sorry for my English

I think the problems is this mindset about:

If someone wants to accomplish some complex thing then someone has to learn some complex background knowledge about the subject and also may have to use sophisticated tools which are also complex (and not cheap)…

…so everything cames at a price (money and/or time)… there isn’t such a thing as easy

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Okay this one, I’m thinking that to stay on Blender (that’s why I’m hoping Blender Measurement has CAD-Like Measurement) or learn CAD for perfection and ofcourse learning CAD UI and Tools is another few days or weeks which for me is a waste of time because what I’m making is for a one-time project only and I’m not into drafting.

Blender uses 32 bit floating point numbers. That is around 7 digits of decimal precision. Some decimal numbers cannot be represented as precise as others in binary that’s why ‘around’. If you need more than 6 decimal places, Blender is not for you and you should consider using CAD software dedicated for precise design like Fusion360 or something like that. 32 bits is still a lot of precision.

In what situation do you actually need 7 significant digits in a number? It’s not like Blender is limited to 7 digits in total, it’s significant digits, so you could have 1234567000000000 or 0.0001234567 as vertex coordinates and they would still be saved precisely. It is a real limitation, you can actually notice, but is it a really significant limitation? I cannot think of any real objects relevant in my life that are manufactured to that precision in any units. Can you?

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Thanks again! you can check my replies to others for your comment.

Thanks for all your comments and pointing me out! I appreciated that a lot!

About decimal places, I’m good now but i think viewport measurement is having a display issue? We know viewport measurement only show 2 decimal places

I enter 1.1665 then when i enter it becomes 1.17? The actual measure is still 1.1665 but viewport measurement giving round off? So it’s confusing right like what’s round off for? Like you need to click to see actual measure instead just showing 1.16

What amount of positions after the decimal point to displace and what amount to store is something what even also very different in … for example in spreadsheets… or do you think a display of

###.##

is informative when the actual number reaches 1000 ??