Swell Shrink Factor Calculator

The Swell Shrink Factor calculator helps you find soil volume changes with ease. It works with bank, loose, and compacted soil.

Soil can change volume during digging and compaction. Digging can make soil expand. This is called swell. Compaction can reduce soil volume. This is called shrink.

You can use this tool for earthwork jobs, road work, and site plans. It can also help with soil haul and fill estimates.

The tool works in both swell and shrink modes. It can find the new volume, bank volume, or percent change.

Swell Shrink Factor Formula

The formula depends on the soil state you want to find.

Swell Factor Formula

The swell factor shows how much soil expands after digging.

Swell Factor = 1 + (Swell % ÷ 100)

Loose Volume = Bank Volume × Swell Factor

To find swell percent:

Swell % = [(Loose Volume ÷ Bank Volume) − 1] × 100

For example, 100 m³ of bank soil with 25% swell gives:

Swell Factor = 1 + (25 ÷ 100) = 1.25

Loose Volume = 100 × 1.25 = 125 m³

So, 100 m³ becomes 125 m³ when loose.

Shrink Factor Formula

The shrink factor shows how much soil volume stays after compaction.

Shrink Factor = 1 − (Shrinkage % ÷ 100)

Compacted Volume = Bank Volume × Shrink Factor

To find shrinkage:

Shrinkage % = [1 − (Compacted Volume ÷ Bank Volume)] × 100

For example, 100 m³ of bank soil with 15% shrink gives:

Shrink Factor = 1 − (15 ÷ 100) = 0.85

Compacted Volume = 100 × 0.85 = 85 m³

So, 100 m³ of bank soil gives 85 m³ of compacted soil.

How to Use Online Swell Shrink Factor Calculator

You can use the Swell Shrink Factor calculator in a few simple steps.

1. Choose Swell or Shrink mode.
2. Choose what you want to find. You can find volume, bank volume, or percent change.
3. Enter the known soil volume and pick its unit.
4. Enter the swell or shrinkage percent when needed.
5. Click the calculate button. The tool converts the volume to m³, applies the formula, and shows the result.

The calculator supports m³, ft³, yd³, and liters. It handles the unit conversion for you.

Example Swell Shrink Factor Calculation

Suppose a job has 500 ft³ of bank soil. The soil has a 20% swell rate.

First, find the swell factor:

Swell Factor = 1 + (20 ÷ 100)

Swell Factor = 1.20

Now find the loose volume:

Loose Volume = 500 × 1.20

Loose Volume = 600 ft³

So, 500 ft³ of bank soil becomes 600 ft³ of loose soil.

For shrink, suppose you have 500 m³ of bank soil. The shrink rate is 10%.

Shrink Factor = 1 − (10 ÷ 100)

Shrink Factor = 0.90

Compacted Volume = 500 × 0.90

Compacted Volume = 450 m³

This shows why swell and shrinkage factors matter in earthwork.

Final Verdict

The Swell Shrink Factor calculator makes soil volume work much easier. It uses the volume ratio between bank, loose, and compacted soil.

It can help answer questions like what is swell factor, how to calculate swell factor, and how to calculate shrinkage.

The same basic idea helps with earthwork shrinkage factor calculation. However, terms such as oil shrinkage factor, shrink swell index, and soil map data can use different methods. Always use the method that fits your field.

FAQs

What is swell factor?

Swell factor shows how much soil expands after excavation. It equals loose volume divided by bank volume.

How do you calculate swell factor?

Use this formula:

Swell Factor = Loose Volume ÷ Bank Volume

You can also use:

Swell Factor = 1 + (Swell % ÷ 100)

How do you calculate shrinkage factor?

Use:

Shrink Factor = 1 − (Shrinkage % ÷ 100)

You can also find it from volume:

Shrink Factor = Compacted Volume ÷ Bank Volume

How is shrink calculated?

Shrinkage is found from the loss in volume:

Shrinkage % = [1 − (Compacted Volume ÷ Bank Volume)] × 100

What is the equation for shrinkage?

The main shrinkage equation is:

Shrinkage % = [1 − (VC ÷ VB)] × 100

Here, VC means compacted volume. VB means bank volume.

How do you calculate % shrinkage?

Divide compacted volume by bank volume. Subtract that result from 1. Then multiply by 100.

What is shrink swell?

Shrink swell means the change in soil volume during excavation and compaction. Soil may swell when dug and shrink when compacted.

How do you calculate shrink swell index?

A shrink swell index test uses soil data to measure volume change. Its method can differ from the simple volume factor used by this calculator. Use the test method required for your soil or project.

How do you calculate oil shrinkage factor?

Oil shrinkage uses a different engineering method. It relates oil volume changes to pressure, temperature, and fluid properties. It isn't the same as soil shrinkage.

What is the formula for shrinkage?

For this calculator:

Shrinkage % = [1 − (Compacted Volume ÷ Bank Volume)] × 100