You can switch your estimation method even after creating a Project. Switching will map existing data estimation values to new appropriate estimation values automatically. The change will impact project graphs and charts as well. Before making this change, bounce off your need or requirement of changing the method with the team and (probably) stakeholders as well.

Once you change an estimation method, values are mapped according to the new method. You can not revert back this change completely. Changing back to original method might not give you exact original values.

**In this article we will discuss following things:**

User Stories supported estimation methods are “Hours” (01-99) and “Points”. You can choose among different Point Estimate methods:

**Linear**(1,2,3,4,5,6…99,100)**Fibonacci**(0,1,2,3,5,8,13)**Scale-100**(0, 0.5, 1, 2, 3, 4, 5, 8, 13, 20, 40, 100)**T-Shirt Size**(XS, S, L, XL, XXL)

Note:Once the Estimation method has been changed, it will not be possible to revert to the old Burndown charts.

If you change your estimation method, then follow the list to see the impacts.

## 1. T-shirt Conversion

Impacts of changing from T-shirt to other point estimates are given below.

### 1.1 To Linear

Each point on the T-shirt scale will be converted to the appropriate suitable value on the Linear scale. E.g. T-shirt M will be converted into Linear 2.

T-shirt scale mapping with Linear scale: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 1.2 T-shirt to Fibonacci

Each point on the T-shirt scale will be converted to the closest minimum value on the Fibonacci scale. E.g. T-shirt L will be converted into Fibonacci 3.

T-shirt scale mapping with Fibonacci: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 1.3 T-shirt to Scale

Each point on the T-shirt scale will be converted to the same value on the Linear scale. E.g. T-shirt M will be converted into Linear 2.

T-shirt scale mapping with Scale: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 1.4 T-shirt to Hours:

Each point on the T-shirt scale will be converted to the exact or closest maximum value in Hours. Conversion also depends on multiple values. E.g, If you set multiple as 6.5

A T-shirt of size XXL, will be converted to Hours 99.

The T-shirt to Hours conversion is mapped as: XS=0, S=1, M=2, L=4, XL=8, XXL=16

Where 1 Point = 0.5 Hours

## 2. Linear Conversion

Impacts of changing from Linear to other point estimates are given below.

### 2.1 Linear to Fibonacci

Each point on the Linear scale will be converted to the closest minimum value on the Fibonacci scale. E.g. Linear 7 will be converted to Fibonacci 5.

### 2.2 Linear to Scale

Each point on the Linear scale will be converted to the closest minimum value on the Scale-100. E.g. Linear 7 will be converted to Scale 5.

### 2.3 Linear to T-shirt

Each point on the Linear scale will be converted to the closest minimum value on the T-shirt. E.g. Linear 7 will be converted into T-shirt L.

The T-shirt scale is: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 2.4 Linear to Hours

Each point on the Linear scale will be converted to the exact or closest maximum amount in Hours, after the selected multiple values been applied. E.g. Linear 90 with multiple 10.0, will be converted to Hours 99.

## 3. Fibonacci Conversion

Impacts of changing from Fibonacci to other point estimates are given below.

### 3.1 Fibonacci to Scale

Each point on the Fibonacci scale will be converted to the same value on the Scale-100. E.g. Fibonacci 8 will be converted into Scale 8.

### 3.2 Fibonacci to Linear

Each point on the Fibonacci scale will be converted to the same value on the Linear scale. E.g. Fibonacci 7 will be converted to Linear 7.

### 3.3 Fibonacci to T-shirt

Each point on the Fibonacci scale will be converted to the closest minimum value on the T-shirt. E.g. Fibonacci 13 will be converted into T-shirt XL.

The T-shirt scale is: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 3.4 Fibonacci to Hours

Each point on the Fibonacci scale will be converted to exact or closest maximum amount in Hours after the desired multiple values has been applied. E.g. Fibonacci 13 with multiple 8.0, will be converted to Hours 99.

## 4. Scale Conversion

Impacts of changing from Scale to other point estimates are given below.

### 4.1 Scale to T-shirt

Each point on the Scale-100 will be converted to the closest minimum value on the T-shirt. E.g. Scale 5 will be converted into T-shirt L.

The T-shirt scale is: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 4.2 Scale to Fibonacci

Each point value within 13 on the Scale-100 will be converted to the same value on the Fibonacci scale. However, Scale points bigger than 13 (i.e. 20, 40 & 100) will all be converted to the Fibonacci max. value 13. E.g. Scale 40 will be converted to Fibonacci 13.

### 4.3 Scale to Linear

Each point on the Scale-100 will be converted to the same value on the Linear scale. E.g. Scale 7 will be converted to Linear 7.

### 4.4 Scale to Hours

Each point on Scale-100 will be converted to the closest maximum value in Hours after the desired multiple values has been applied. E.g. Scale 40 with multiple 3.5, will be converted to Hours 99.

## 5. Hours Conversion

Impacts of changing from Hours to other point estimates are given below.

### 5.1 Hours To Linear

Each value in Hours will be converted to the closest maximum amount in the Linear scale after the desired multiple values has been applied. E.g. Hours 51 with multiple 2.0, will be converted to Linear 100.

### 5.2 Hours To T-shirt

Each value in Hours will be converted to the closest minimum value on the T-shirt scale after the desired multiple values has been applied. E.g. Hours 4 with multiple 3.0, will be converted to T-shirt XL.

The T-shirt scale is: XS=0, S=1, M=2, L=4, XL=8, XXL=16

### 5.3 Hours To Scale

Each value in Hours will be converted to the closest maximum value on the Scale-100 after the desired multiple values has been applied. E.g. Hours 52 with multiple 2.5, will be converted to Scale value 100.

### 5.4 Hours To Fibonacci

Each value in Hours will be converted to the closest minimum value on the Fibonacci scale after the desired multiple values has been applied. E.g. Hours 5 with multiple 4.5, will be converted to Fibonacci 13.