# How to Calculate Size of Septic tank | Standard Size of Septic tank

Hello, Friend in this article I am going to explain you How to calculate size and capacity of septic tank, and what is standard size of septic tank for 3, 4, 5, 6, 7, 8, 10, 15, 20, 30, and 50 users, and I will also tell you what is the septic tank. I hope that after reading this article all your doubts related to septic tanks will be cleared.

A septic tank is a very important part of any residential or commercial building. In such a situation, it is important to know what is the standard size of septic tank.

## What is Septic Tank?

Septic tanks are made from RCC, PCC, brickwork, plastic, fiberglass, or steel which are built underground. Which is usually of two chambers that are connected to each other. The main function of a septic tank is to decompose human waste. The septic tank is connected to the toilet by a pipe through which human waste enters the first chamber of these tanks, which is decomposed by anaerobic bacteria. The second chamber of the septic tank is connected to the drainage system by a pipe. Through which the decomposed waste and water come out of the chamber.

Readymade septic tanks are also available in the market of the America as well as in many countries of Western Europe.

### How to calculate Size and Capacity of Septic tank

A septic tank is a very important part of any building. Whether the building is residential or commercial. In such a situation, it is a matter of concern what size septic tank is required for your house or building. So you do not need to worry because after reading this article you will learn how to calculate size of septic tank.

Generally, septic tank is made in 2 types of shapes, one rectangular and the other in round shape. Therefore, different formulas are used to calculate the size of rectangular and round-shaped septic tanks.

### Formula for Round Shaped septic tank capacity

If you want to calculate Round shape septic tank capacity in gallons then you should use this formula:

The formula for the capacity of septic tank in gallons = (πR2h) × 7.5 (Radius and height should be in feet).

Where π is equal to 3.14, “R” represents the radius, and “h” represents the Height or depth of the tank. and 7.5 for the gallon. If you want the size of the septic tank then don’t multiply by 7.5.

If you want to calculate Round shape septic tank capacity in liters then you should use this formula:

The formula for capacity of septic tank in liters = (πR2h) × 1000 (Radius and height should be in meters).

Where π is equal to 3.14, “R” represents the radius, and “h” represents the Height or depth of the tank. and 1000 for the liters.

### Formula for Calculate Rectangular shaped septic tank capacity

If you want to calculate Rectangular shape septic tank capacity in gallons then you should use this formula:

The formula for the capacity of septic tank in gallons = (L × B × H) × 7.5 (Radius and height should be in feet).

Where “L” represents the length of the septic tank, “B” represents the breadth of the tank, and “H” represents the Height of the tank. and 7.5 for the gallon.

If you want to calculate septic tank capacity in liters then you should multiply by 1000 instead of 7.5.

### Standard Size of septic tank

The standard size of a septic tank can be determined based on the number of people using the septic tank or on the basis of the size of the buildings/homes. but I will tell you the standard size of septic tank for 5 users.

According to IS Code, 2470-1963 standard size of septic tank should be 8 × 4.5 × 6 feet for 5 users.

### How to calculate septic tank size according to my need

To calculate size of septic tank according to your need you can use this formula.

Capacity of septic tank = A + P (RQ + NS).

Where According to British standard code A = 2000, P represents the number of users, and (RQ + NS) = 180.

### Septic tank Size for 3 users

Hence, the number of users is 3.

The capacity of septic tank for 3 users = A + P (RQ + NS).
= 2000 + 3 (180).
= 2000 + 540 = 2540 liters.

So, For 3 users 2540 liters of septic tank is required.

### Septic tank Size for 4 users

Hence, the number of users is 4.

The capacity of the septic tank for 4 users = A + P (RQ + NS).
= 2000 + 4 (180).
= 2000 + 720 = 2720 liters.

So, For 4 users 2720 liters of septic tank is required.

### Septic tank Size for 5 users

Hence, the number of users is 5.

The capacity of septic tank for 5 users = A + P (RQ + NS).
= 2000 + 5 (180).
= 2000 + 900 = 2900 liters.

So, For 5 users 2900 liters of septic tank is required.

### Septic tank Size for 6 users

Hence, the number of users is 6.

The capacity of septic tank for 6 users = A + P (RQ + NS).
= 2000 + 6 (180).
= 2000 + 1080 = 3080 liters.

So, For 7 users 3080 liters of septic tank is required.

### Septic tank Size for 7 users

Hence, the number of users is 7.

The capacity of septic tank for 7 users = A + P (RQ + NS).
= 2000 + 7 (180).
= 2000 + 1260 = 3260 liters.

So, For 7 users 3260 liters of septic tank is required.

### Septic tank Size for 8 users

Hence, the number of users is 8.

The capacity of septic tank for 8 users = A + P (RQ + NS).
= 2000 + 8 (180).
= 2000 + 1440 = 3440 liters.

So, For 8 users 1440 liters of septic tank is required.

### Septic tank Size for 9 users

Hence, the number of users is 9.

The capacity of septic tank for 9 users = A + P (RQ + NS).
= 2000 + 9 (180).
= 2000 + 1620 = 3620 liters.

So, For 9 users 3620 liters of septic tank is required.

### Septic tank Size for 10 users

Hence, the number of users is 10.

The capacity of septic tank for 10 users = A + P (RQ + NS).
= 2000 + 10 (180).
= 2000 + 1800 = 3800 liters.

So, For 10 users 3800 liters of septic tank is required.

### Septic tank Size for 15 users

Hence, the number of users is 15.

The capacity of septic tank for 15 users = A + P (RQ + NS).
= 2000 + 15 (180).
= 2000 + 2730 = 4730 liters.

So, For 15 users 4730 liters of septic tank is required.

### Septic tank Size for 20 users

Hence, the number of users is 20.

The capacity of septic tank for 20 users = A + P (RQ + NS).
= 2000 + 20 (180).
= 2000 + 3600 = 5600 liters.

So, For 20 users 5600 liters of septic tank is required.

### Septic tank Size for 25 users

Hence, the number of users is 25.

The capacity of septic tank for 25 users = A + P (RQ + NS).
= 2000 + 25 (180).
= 2000 + 4500 = 6500 liters.

So, For 25 users 6500 liters of septic tank is required.

### Septic tank Size for 30 users

Hence, the number of users is 30.

The capacity of septic tank for 30 users = A + P (RQ + NS).
= 2000 + 30 (180).
= 2000 + 5400 = 7400 liters.

So, For 30 users 7400 liters of septic tank is required.

### Septic tank Size for 50 users

Hence, the number of users is 50.

The capacity of septic tank for 50 users = A + P (RQ + NS).
= 2000 + 50 (180).
= 2000 + 9000 = 11000 liters.

So, For 50 users 11000 liters of septic tank is required.

You can calculate the size of the septic tank according to your requirement by changing the value of the user through this formula.

### Size of septic tank for 100 users

Hence, the number of users is 100.

The capacity of the septic tank for 100 users = A + P (RQ + NS).
= 2000 + 100 (180).
= 2000 + 18000 = 20000 liters.

So, For 100 users 20000 liters of septic tank is required.

You can calculate the size of the septic tank according to your requirement by changing the value of the user through this formula.

### Size of septic tank for 200 users

Hence, the number of users is 200.

The capacity of septic tank for 200 users = A + P (RQ + NS).
= 2000 + 200 (180).
= 2000 + 36000 = 38000 liters.

So, For 200 users 38000 liters of septic tank is required.

You can calculate the size of the septic tank according to your requirement by changing the value of the user through this formula.

### Septic tank size for 3-bedroom house

In some circumstances, the septic tank size is determined on the basis of the number of bedrooms in the house rather than the number of people living in the house. According to US Standard, a septic tank of 1000 gallons or 27 square feet size is best suited for a 3-bedroom house.

### Septic tank size for 4-bedroom house

In some circumstances, the septic tank size is determined on the basis of the number of bedrooms in the house rather than the number of people living in the house. According to US Standard, a septic tank of 1200 gallons or 34 square feet size is best suited for a 4-bedroom house.

### Septic tank size for 5-bedroom house

In some circumstances, the septic tank size is determined on the basis of the number of bedrooms in the house rather than the number of people living in the house. According to US Standard, a septic tank of 1500 gallons or 40 square feet size is best suited for a 5-bedroom house.

### Septic tank size for 6-bedroom house

In some circumstances, the septic tank size is determined on the basis of the number of bedrooms in the house rather than the number of people living in the house. According to US Standard, a septic tank of 1750 gallons or 47 square feet size is best suited for a 6-bedroom house.

#### Conclusion

Guys In this article I have explained what is septic tank, how to calculate septic tank size and septic tank size calculation formula, and many more about septic tanks I hope you liked this article.

#### FAQ

Septic tank size for 100 users

Septic tank size for 100 users should be approx 20000 liters. This is an ideal size of the septic tank for 100 users.

### 1 thought on “How to Calculate Size of Septic tank | Standard Size of Septic tank”

1. Very useful information…thnk you