# Thread: Formula for area input parameter

1. ## Formula for area input parameter

anyone knows if its possible to create a family that contains a mass box that has an input option of area. let's say I need a base area of 200 sf. so I input the area then one dimension (whether its length or width) and revit would automatically find the other dimension and create the box.

this could be very useful for conceptual programming phase.

2. ## Re: Formula for area input parameter

Create the family with length, width, and area parameters. Area and Length (for example) will be input, and Width will be calculated. Add a formula to the Width field that looks like = Area / Length and you'll be ready to go.

To make it simple during programming, make all 3 parameters as instance parameters. That way you can push/pull the boxes as you place them around on your plan view.

3. ## Re: Formula for area input parameter

Originally Posted by patricks
Create the family with length, width, and area parameters. Area and Length (for example) will be input, and Width will be calculated. Add a formula to the Width field that looks like = Area / Length and you'll be ready to go.

To make it simple during programming, make all 3 parameters as instance parameters. That way you can push/pull the boxes as you place them around on your plan view.

I added three parameters named Length Width and Area, I assigned the rite properties for each. I made them instance parameters.

now when I'm inputting the formula ( =Area / Length) I'm getting a window saying (Division by zero)

What's that?

Note that I started a family and chose Mass as a template.

4. ## Re: Formula for area input parameter

Is is as simple as your Length Parameter = 0? If so then the error mesage is as expected, since you cant divide by zero. Change the Length Parameter to be something else

5. ## Re: Formula for area input parameter

any chance that you can share that family ?? been looking for that tool from the beggining of time..

a treat, attachd

6. ## Re: Formula for area input parameter

I am looking for the same thing. I am in schematic design phase. The client would like a 90,000 sf building. We know to achieve optimal daylighting and multi tenant space planning we want the building width to equal 90'. The length and building height are variable. I could go 4 stories at approx. 250' long or 3 stories at approx. 350'. I also know I need 15' floor to floor. Is this even possible to do in REVIT? To keep the width and an overall square footage constant as the building gets taller and longer/shorter? I am using 2011.

7. ## Re: Formula for area input parameter

use the attached mass in post below .. I am sure another parameter could be added for volume.. !! input only one parameter while other side is fixed....
The attached mass is 'mickey mouse' but helped me a lot !!