# Simulation accuracy

**URL:** https://community.freefem.org/t/simulation-accuracy/562
**Category:** General Discussion
**Created:** [September 2, 2020, 7:03am UTC](https://community.freefem.org/t/simulation-accuracy/562 "2020-09-02T07:03:38Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Vincent](https://avatars.discourse-cdn.com/v4/letter/v/e9bcb4/32.png) [@Vincent](https://community.freefem.org/u/Vincent)
#### Post date: [September 2, 2020, 7:03am UTC](https://community.freefem.org/t/simulation-accuracy/562/1 "2020-09-02T07:03:38Z")

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Hello,  
I would like to ask about the accuracy that FreeFem++ can simulate?  
Can the simulation accuracy reach 10^(-5)?

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### Author: ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [September 4, 2020, 9:50am UTC](https://community.freefem.org/t/simulation-accuracy/562/2 "2020-09-04T09:50:14Z")

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1. What is accuracy?
2. if you have good error estimator, yes.

This this your problem and it is not automatic.

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### Author: ![Vincent](https://avatars.discourse-cdn.com/v4/letter/v/e9bcb4/32.png) [@Vincent](https://community.freefem.org/u/Vincent)
#### Post date: [September 5, 2020, 5:58am UTC](https://community.freefem.org/t/simulation-accuracy/562/3 "2020-09-05T05:58:47Z")

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Thanks for your reply. I am so happy.

My question is, if you want to simulate a real device, how much accuracy can be achieved by FreeFEM++.

For example, to simulate a cube, how much can its side length be accurate? (for example, 10 ^ (- 5) m)

Sorry, maybe I didn’t describe the problem clearly.