I can give you a rough estimate of the amount of wood you will need.

我可以粗略估计一下你所需要的木材量。

We were only able to make a rough estimate of how much fuel would be required.

我们只能对所需燃料的量作一个粗略估计。

As a rough estimate, Nigeria is three times the size of Great Britain.

粗略估计,尼日利亚是大不列颠的三倍大。

This is a rough estimate of the costs.

这是对费用的大致估计。

But, remember, this is a very rough estimate.

但，记住，这只是一些粗糙的计算估计。