French Drain Calculators: How To Measure Your French Drain?

Keeping your property safe from water damage and other problems is challenging. It is easier if you are familiar with the subject. That is why many property owners hire contractors to maintain their indoor and outdoor spaces. You can do several simple things to save money and avoid problems. Installing french drain calculators is inexpensive, simple, and needs little effort. How much will it set you back?


We’ve come up with the response if you want to know how much a french drain will cost– french drain calculators, which will give you an accurate estimation of expenses based on your particular needs.

French Drain Calculators

One of your french drain’s most crucial parts is the gravel. You can use french drain calculators to determine how many bags of gravel you’ll need to line your trench. Calculating your need in advance will save you money because gravel bags cost roughly $12 each.

French Drain Calculators: French Drain Cost

Once you have the information, use french drain calculators to estimate your installation costs. By putting a french drain in your yard, you can save more than $100 per year on irrigation bills. 

Depending on the size of your property, this translates to savings of roughly $8 per month or perhaps more.

French Drain Calculators: How To Use Them?

Please remember that the numbers below are simply estimations before using french drain calculators. They do not represent exact costs in your specific circumstance. As a general guideline, you can anticipate paying between $2,000 and $5,000 for a french drain.

Recognize that there are primarily two kinds of french drains: drainage trench and standard pipe. The drain type that best suits your needs must be chosen. 

Once you’ve chosen your type, enter the necessary details into french drain calculators to get a quick quote. When you’re through, you’ll be aware of the exact price of a french drain!

French Drain Calculators: Tips For Measuring Your French Drain

You must compute two things to determine how much gravel you will need to use to fill your french drain trench:

  • the trench’s breadth, length, and depth
  • the pipe’s actual size in volume

We will subtract the pipe volume from the trench volume once we have these two figures. The quantity of gravel you will want is the figure we arrive at.

French Drain Calculators: Measuring the Dimensions 

The width, depth, and dimensions of your trench should be noted and recorded. It’s vital to remember that your trench’s measurements won’t be constant throughout its length and could change as a result of minute mistakes made during digging.

Measure the breadth and depth frequently to ensure you order only a little gravel. The average width and depth can be calculated by taking the average of the data points. 

We advise either making the trench more uniform or calculating the volume of constant portions separately and adding them together at the end to get the gravel you’ll need if there are significant discrepancies between the breadth and depth of the french drain trench.

French Drain Calculators: Measuring The Pipe

The pipe’s name will include its dimensions when you purchase it for your french drain. Instead of measuring the line itself, we advise using these measurements for precision. If you need help remembering these dimensions, look at your receipt.


Alternatively, you could always gauge the diameter and length directly. In order to acquire the most accurate measurement result, it is advised that you lay the pipe flat on a table and measure its width at a 90-degree angle from the table.


Find out more about determining the precise gravel quantity and overall cost of your backyard french drain.

1. How much gravel will I need for a 100-foot french drain?

Multiplying the trench length by the breadth and depth will yield the amount of gravel required for a 100′ french drain. One hundred feet times 4 inches equals 400 cubic feet of gravel if you intend to lay down 4 inches of it. 

You will need roughly 26 bags because each bag has a cubic volume of 1.5 cubic feet, so divide 400 by 16 to get the number of packs you need.

2. How much gravel will a 50-foot french drain require?

Multiply the length of the trench by the breadth and depth to determine the amount of gravel required for a 50′ french drain. Fifty feet times 4 inches equals 200 cubic feet of gravel if you intend to lay down 4 inches of it. Since each bag is 1.5 cubic feet, divide 200 by 16 to get the approximate amount of gravel you’ll need, which comes out to roughly 13 bags.

3. What does a french drain cost per foot?

Between $450 to $550, or around $3 to $4 per linear foot, is the general cost of a french drain for supplies and labor. The cost increases as more surface areas are covered in the trench.

4. How is the size of a french drain determined?

Multiplying the surface area, slope, and annual rainfall will get the size of a french drain.

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Michael Bowen

Michael Bowen

Michael Bowen is an ambitious entrepreneur who has been in the business of building homes since he was 19. Michael's commitment to honesty, integrity, and high-quality workmanship has earned him a reputation as one of the best in the business.

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