3 T-Shirt Sizing Agile Methods for Better Team Estimates (2023)

T-shirt sizing agile is an relative estimation technique. It is utilized to track and give a rough estimate to how much time or effort a epic / feature / task would be expected to take. It is my go to agile estimation tool when a product owner wants to quickly assess the size of their product backlog or when attending agile portfolio planning.

The opposite of t-shirt sizing would be an absolute agile estimation technique such as story points.

T-shirt sizing also helps make a determination of their agile teams ability, key stakeholders and dependencies. Using this information the product owner can clearly explain their priorities and team members can have a rough idea of who is responsible for a particular task and when they are responsible for it.

Table Of Contents

(Video) T-shirt Size Estimation - Better Than Story Points?

  1. When to do T Shirt Sizing
    • How to Do T-Shirt Sizing Planning Poker
    • Sprints to Epic Estimating Chart
  2. T-Shirt Sizing Agile Example
  3. Benefits and Pitfalls
  4. Tools for Creating T-Shirt Sizing Online
  5. Estimating Alternatives to T Shirt Sizing in Agile
    • Affinity Mapping Product Features
    • What is affinity grouping in Agile?

This agile estimation process is done by assigning each particular tasks with T-shirts sizes that can range from extra small to XXL. While t-shirt sizing estimation is mostly used by software development teams and engineers, it is an applicable tool for any type of team.

To help the teams align it to their day to day work, I put up a guide on how many sprints of work do they think the piece of work would take. This tactic works if your sprint is 2 weeks or 1 month they still have a relative time frame to complete the task.

When to do T Shirt Sizing

T-shirt sizing in Agile projects would be used during project kick-off to measure how much work is involved and if you have the appropriate people resourcing in the Agile team. This helps get management off your back as they are the ones who want estimates with endless backlogs even though its not the best thing for your product.

Estimates could be considered anti-agile or product management as it should matter how long it takes you should only be working on the most important thing to bring the most value to the product #NoEstimates

It can also utilized during agile portfolio planning to have a high level estimate of upcoming features a team can consider taking on without having to fully decompose to an absolute level such story point level. I do think relative estimates are good to help with capacity planning but should be taken with a grain of salt and not considered project schedules – that is the biggest mistake management make.

You should consider t-shirt size estimation when you need a quick estimate for the number of items and it allows for teams that are new to the agile estimation techniques a way to perform a better estimation method.

How to Do T-Shirt Sizing Planning Poker

To facilitate a planning poker t-shirt sizing session follow these steps:

(Video) [PART #4] T-Shirt Sizing Estimation | Agile Estimation Techniques | Planning Poker Game

  1. The agile product team are provided an overview of what each t-shirt size represents and provided the cards.
  2. The product team has been presented with the necessary information by the product owner. This could be done using a Agile charter or business case or simply an epic
  3. The team would select a playing card that represents their estimate and it is revealed to the estimators.
  4. If there are differences in the value each team member selects, they discuss their estimates and after discussion, reselects another estimate card.
  5. This process is repeated until there is a common goal on all of the values.

Agile development teams use planning poker in an agile project to estimate story points in a realistic fashion. Planning poker requires the consensus of the entire team and is structured in a way that the product owner would read an overview of a user story or describe a feature to those responsible in the development team for estimating the amount of work that is required.

Agile Epics & T-Shirt Sizing

Epics are parts that we want to have built into our product or process. They are large groupings that have the ability to be broken down into smaller user stories. Analyzing an Epic must include the Minimum Viable Product (MVP), which is considered the bare minimum requirement for a new product or feature.

While estimating Epics in the beginning stages can be difficult due to the limited amount of data, it is done through T-shirt sizing and is refined over time throughout the implementation of MVP.

Typically, Epics are done in a sprint time frame. The scrum team would initially meet for sprint planning to make a determination of which items should be handled in each sprint. Each T-shirt size correlates to the amount of sprints it takes to measure the completion of each Epic:

Sprints to Epic Estimating Chart

S – 1 Sprint

M – 2 to 4 Sprints

L – 5 to 6 Sprints

XL – 7 or more sprints.

Working in XL sizes are not ideal. If you have an Epic that is larger than 6 sprints, it would be important to break them down.

(Video) T-shirt Method for Agile Estimating

Agile Estimating Technique

T-Shirt Sizing Agile Example

When it comes to making a determination of an epic size when building a new website, it is important to center this build around your project team’s goals. Take for example that you would like to build a website that is designed for the supervisors of an organization to access and have functionality for documentation.

Epics are the big picture and each component of these would need to be broken down into user stories in order for them to have its full functionality.The Epics for developing the site would be divided into sprints and looks like this:

FeatureT-Shirt Size
User ProfileMedium
Forgot PasswordSmall

Benefits and Pitfalls

T-shirt sizing finds itself beneficial because it is a simplified way to have an estimate. Team members have the ability to spend less time thinking about a task or how much time it would take. Tracking t-shirt sizing in a planning session is designed to being a centralized tool so that everyone can see who is doing what and how much.

Subjectivity is common T-shirt sizing pitfall that occurs when implemented in agile development teams. There are times when clarity is needed in order to make distinctions between sizes as well as the ability to track an initiatives associated t-shirt size.

The main premise of the no estimates movement is that estimates do not directly add value to your process or work, so you should find ways to reduce the estimation process or even stop it if possible

Stop Estimating: The #NoEstimates Movement in Agile – DZone Agile

Tools for Creating T-Shirt Sizing Online

There are useful tools available that makes it easier for your team to create T-shirt sizing.

(Video) T-Shirt Estimation - Agile Methods - Quick 4 min Guide -Being Agile

Two popular tools to utilize for creating T-Shirt sizing are Asana and Trello.

Asana: Has a method for t-shirt sizing for content projects. It is an assessable tool with a sharing function that allows for your workload to be managed for your team.

Trello: Utilizes custom fields that cater to assigning specific t-shirt sizes for projects. This program allows for you to make rules to have your cards organized in the order that you would like for it to be in. Trello also implements a sharing function that allows for your team have access.

Estimating Alternatives to T Shirt Sizing in Agile

A few alternatives to T-Shirt sizing in agile would be affinity mapping and planning poker. These two agile estimation processes carry a significant level of importance in the scrum process to best determine how much effort is required in development.

Fibonacci Series & Story Points

Story points represent the size, difficulty, and effort that is required for the implementation of a user story. The Fibonacci sequence is utilized as a scale to more accurately measure how much work goes into each sprint. The is a linear scale that is generated by adding two previous numbers together to produce the next value in the sequence. The sequence would be recorded like this: 0, 1, 1, 2, 3, 5, 8, 13, 21.Each story point estimate would then be assigned a number that is represented on the scale.

Affinity Mapping Product Features

Affinity refers to comparable backlog items related to ether types of code, varying areas of a product, or the type of effort required within product development. When it comes to affinity mapping within the agile estimation technique, each team will group items of similar size together.

What is affinity grouping in Agile?

To execute affinity mapping, the person facilitating the project would place the backlog items onto sticky notes and place them onto a wall. The team would then place them into the correct sizing category. After this is done, they will discuss each item to evaluate whether or not they are assigned appropriately. An important component of this process is that the team must move quickly and not overthink.

(Video) How to Estimate User Stories in Agile Scrum? (Story points & T-Shirt Size Estimation MADE SIMPLE)


Which technique is used for sizing and resizing in agile? ›

Popular estimating methods in an agile development environment include story points, dot voting, a bucket system, affinity mapping, and t-shirt sizing. T-shirt sizing is a common agile estimation technique that can be very effective for long-term planning or helping your team get used to relative estimating.

How can I estimate my t-shirt size? ›

Here's how to measure a t-shirt:
  1. Lay the shirt on a flat surface.
  2. Get the length by measuring from the top of the collar to the bottom of the t-shirt.
  3. Measure the waist to ensure the shirt is small or large enough for the desired body type.
  4. Place the tape measure across the chest area to get the dimensions.
29 Aug 2022

What is sizing and estimation in agile? ›

In Agile, estimates of size and duration are distinct and separated. The measure of size commonly used in Agile is story points. Story points are a relative measure of the size of a user story. A user story estimated as 2 story points should be twice as big, complex, or risky as a story estimated as 1 story point.

What are the t-shirt sizes? ›

SizeTo fit Chest Size
6 more rows

What is Agile T-shirt sizing? ›

T-shirt sizing is an agile estimation technique that uses relative sizing to estimate IT project costs. While beneficial in the cost estimation process, it's also important to highlight key characteristics and best practices to ensure an appropriate design and full adoption of this technique. June 18, 2020.

What does T-shirt size mean in agile? ›

What is t-shirt sizing? T-shirt sizing is a project estimation and capacity planning tool that helps you track how much time or effort an initiative will take. To do this, you assign each project or task a t-shirt size—from Extra Small to XXL—to represent that task's relative effort.

Why is it called t-shirt sizing? ›

The term "t-shirt sizing" is originated from the way t-shirt sizes are mentioned in the U.S. Instead of giving them a number 2,3, and 4, they are given sizes, extra small (XS), small (s), medium (m), and so on.

What is t-shirt size in Jira? ›

T-shirt sizes make for a quick and universally-understood system for estimating the level of effort required to complete a task. Teams estimating with T-shirt sizes use the values S, M, L, XL and XXL to express a tasks required effort.

How do shirt sizes work? ›

Here's the scoop: The first number on the size tag refers to the neck size and the second number is the sleeve length. So a shirt size “15 34/35” means that the neck is 15 inches and the sleeve is between 34 and 35 inches.

How many t shirts do you need? ›

How Many Shirts Should I Have? A regular person should have at least 7 shirts in their closet to have a clean one for each day of the week.

How many of each shirt size should I order? ›

So for example, to place the best order if you need 100 t-shirts, you'd select 10 Smalls, 25 Mediums, 30 Larges, 25 XLs, and 10 2XLs. Depending on the shirt style and audience, you may want to add a few 3XL and 4XLs too.
Common size breakdown.
1 Mar 2019

How many hours is 3 story points? ›

Some teams try to map the story points to hours – for example two story points correspond to a task that will take 2-4 hours, and 3 story points can be mapped to tasks from 4 to 8 hours long, and so on.

What are sizing methods that can be applied for estimation? ›

Sizing Methods. The five major sizing methods that are being used by the survey participants included (1) sizing by analogy, (2) function points, (3) Halstead vocabulary, (4) proxies and (5) user stories/story points. The two methods most used were sizing by analogy and function points.

What is sizing in Agile? ›

Sizing Agile Stories with the Relative Sizing Grid

Story Points are the most common unit of measure for Agile Teams that practice relative sizing. The most common scale used for story points is the Fibonacci sequence (1, 2, 3, 5, 8, 13, and so on).

Which are the Agile estimation techniques? ›

Here are some of the most popular Agile estimation techniques in use:
  • Planning Poker. Number-coded playing cards are used to estimate an item. ...
  • Analogy. ...
  • T-Shirt Size Estimation. ...
  • Dot Voting. ...
  • Affinity Mapping. ...
  • The Bucket System Estimation. ...
  • Three-Point Method. ...
  • Fibonacci Sequence for Story Point Estimation.
20 Apr 2021

What is T-shirt mean? ›

A T-shirt, or tee, is a style of fabric shirt named after the T shape of its body and sleeves. Traditionally, it has short sleeves and a round neckline, known as a crew neck, which lacks a collar.

What is the average customer size in Agile projects? ›

Team sizes across the software development industry

Agile itself recommends team sizes of 3 to 9 members and many software engineering managers believe 7 members is the magical sweet spot.

What do you mean by Agile methodology? ›

The Agile methodology is a way to manage a project by breaking it up into several phases. It involves constant collaboration with stakeholders and continuous improvement at every stage. Once the work begins, teams cycle through a process of planning, executing, and evaluating.

What is the term used for a measure of the amount of work a team can complete during a single sprint? ›

Velocity is a measure of the amount of work a Team can tackle during a single Sprint and is the key metric in Scrum. Velocity is calculated at the end of the Sprint by totaling the Points for all fully completed User Stories.

Which are the sizing techniques? ›

Sizing Methods. The five major sizing methods that are being used by the survey participants included (1) sizing by analogy, (2) function points, (3) Halstead vocabulary, (4) proxies and (5) user stories/story points. The two methods most used were sizing by analogy and function points.

What is story sizing in Agile? ›

Story points represent the relative sizing of the user story. It is a unit of estimation used by Agile teams to estimate User Stories. When the product owner wants some features to be developed he/she desires to know how soon the team can complete the features and how many resources it will take to complete the work.

Which of the following are methods for sizing user stories? ›

Top 5 User Story Estimation Techniques
  • Planning Poker. This method uses the Fibonacci sequence where user story point values are presented as 0, 1, 2, 3, 5, 8, 13, 20, 40, and 100 on playing cards, associated with different levels of complexity. ...
  • T-shirt Size Estimation. ...
  • Dot Voting. ...
  • Bucket System. ...
  • Affinity Mapping System.
15 Mar 2022

What are estimation techniques in Agile? ›

What is Estimation in Agile? Agile estimation is the process for estimating the effort required to complete a prioritized task in the product backlog. This effort is usually measured with respect to the time it will take to complete that task, which, in turn, leads to accurate sprint planning.

What is the purpose of sizing? ›

Sizing is used during paper manufacture to reduce the paper's tendency when dry to absorb liquid, with the goal of allowing inks and paints to remain on the surface of the paper and to dry there, rather than be absorbed into the paper.

What are the objectives of sizing? ›

Objects of sizing

To improve the weave ability of warp yarn. To maintain good fabric quality by reducing hairiness, weakness, and increasing smoothness and the yarn's strength. To increase the tensile or breaking strength for cellulose yarn. To increase the elasticity.

What do you mean by size estimation? ›

Software sizing or Software size estimation is an activity in software engineering that is used to determine or estimate the size of a software application or component in order to be able to implement other software project management activities (such as estimating or tracking).

How many hours is 3 story points? ›

Some teams try to map the story points to hours – for example two story points correspond to a task that will take 2-4 hours, and 3 story points can be mapped to tasks from 4 to 8 hours long, and so on.

How many hours is 1 story points? ›

People want an easy answer, such as “one story point = 8.3 hours.” The truth is, though, that the relationship, while real, is not quite that easy to quantify and will vary greatly from team to team.
How Many Hours is a Story Point Worth?

How many hours is 5 story points? ›

For 5 story points, the number of hours might need 10 to 15 hours. For 8 story points, the number of hours might need 15 to 20 hours. For 13 story points, the number of hours might need 21 to 30 hours.

Which of the following technique is used for Agile estimating and planning? ›

Planning Poker is an agile estimating and planning technique that is consensus based. To start a poker planning session, the product owner or customer reads an agile user story or describes a feature to the estimators.

What type of estimation do Scrum teams use to size their stories? ›

Therefore, the team can choose an estimation technique which fits the need. Many Scrum teams are using t-shirt sizes or relative story points (but Scrum doesn't prescribe to use any of those). Estimation of new PBIs can be a part of regular product backlog refinement activities.

What is the purpose of Agile estimation? ›

Agile estimation helps for proper planning, management and estimation of the total efforts that will be used for implementing, testing and delivering the desired product to the customers in terms of time within the specified deadlines.

What are story point sizing techniques? ›

Story point estimation is a technique used in Agile project management to replace task estimation in time or money. The smallest tasks are estimated at 1 point and then other tasks are weighed and estimated in accordance with that task.

How do you do project estimation method? ›

Project Estimation Techniques
  1. Top-Down Estimate. ...
  2. Bottom-Up Estimate. ...
  3. Analogous Estimating. ...
  4. Parametric Estimate. ...
  5. Three-point Estimating. ...
  6. What-If Analysis.
7 Jul 2022


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