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Southampton, Hampshire, England

Coding classes in Southampton

What are the best coding classes in Southampton?

Southampton counted 248,922 usual residents at the 2021 Census, and 25.6% of those aged five and over were schoolchildren or full-time students, against 20.4% across England. Ordnance Survey, Great Britain's national mapping service, moved its headquarters to Southampton after a fire in 1841, and its open postcode file is the data behind the project on this page. Modern Age Coders teaches Southampton learners aged six to sixty-seven live online, in small groups of five to ten set by level or one to one, with teachers in India and times arranged in UK hours. Nothing is charged for the first lesson. Afterwards it is USD 100 a month for a group place, or USD 150 a month for lessons with a teacher to yourself.

Southampton has 5,814 postcodes in Ordnance Survey's open Code-Point file. Suppose a program has to find one of them instantly, thousands of times a second. Scanning a list takes 2,907 comparisons on average. A hash table does it in about one: a hash function turns each postcode into a bucket number, and the lookup jumps straight there. But the hash has to be good. The obvious one, adding up the character codes, turns out to produce only 61 different answers for every postcode in the city, because they are all built from the same few letters and digits. It packs 5,814 postcodes into 61 of 7,919 buckets, with 227 in the worst. A well-mixed hash spreads the same keys over 3,901 buckets, seven at most in any one. Knowing why, and how to measure it, is the lesson Southampton's postcodes teach our teenage learners.

Facts last verified 21 September 2026. Teaching is online; no Southampton branch is claimed.

Course picks for Southampton

Four courses for the mapmakers' city

Let the learner's interests lead. Each course starts with a free live lesson, and no card is needed to book.

Browse the course atlas for more than one hundred options and use the coding roadmap to check prerequisites.

The four we are known for

Python, AI, vibe coding and agentic coding

These run underneath everything above. Every one is live and online, placed by ability rather than by age, and the first class is free.

Southampton today

A port city with a strong student presence

From the 2021 Census tables for the Southampton local authority, published by the Office for National Statistics on Nomis.

Southampton, Census 2021
What was countedSouthamptonEngland
Usual residents248,922Not compared
In households238,765, 95.9%Not compared
In communal establishments10,157, 4.1%Not compared
Aged 15 to 1916,752, 6.7%5.7%
Aged 20 to 2426,139, 10.5%6.0%
Aged 25 to 2920,718, 8.3%6.6%
Schoolchildren and full-time students, of 235,126 aged five and over60,197, 25.6%20.4%

The early twenties

Residents aged 20 to 24 made up 10.5% of Southampton, and those aged 25 to 29 another 8.3%, against 6.0% and 6.6% in England.

Learners of every kind

Schoolchildren and full-time students together were 25.6% of residents aged five and over in 2021, with England at 20.4%.

Mostly in households

Some 95.9% of residents lived in households; the other 4.1%, in communal establishments, include people in student halls.

In practice that means learners at every stage. A Southampton learner might be a nine-year-old in Bassett writing a first Python program, a Year 13 student in Sholing finishing A level Computer Science, or someone in their twenties in Ocean Village learning SQL for work, and each joins a group of five to ten at the same level.

The nation's mapmakers

Ordnance Survey's long Southampton story

From Ordnance Survey's own account of its history and its about page.

21 June 1791

Ordnance Survey says this date is officially recognised as its birth, when the Board of Ordnance bought a new Ramsden theodolite to carry William Roy's triangulation forward.

1841

A fire at Ordnance Survey's cramped Tower of London offices prompted a move to a new Southampton headquarters, in an empty former barrack building.

342 million

In the Second World War the Southampton headquarters was bombed and badly damaged, and by 1945 Ordnance Survey had produced 342 million maps for the war effort.

Today Ordnance Survey describes itself as Great Britain's national mapping service. Its head office, Explorer House on Adanac Drive in Nursling, carries a Southampton postal address; its own postcode file places that postcode, SO16 0AS, just over the city boundary in Test Valley. We have no connection with Ordnance Survey. We tell its story because the dataset on this page is one of its open products, published by a mapmaker with nearly two centuries of history in and around the city.

The file we used

Code-Point Open, dataset version 2026.3.0, gives a grid reference and district code for every postcode unit in Great Britain. Its SO file lists 18,624 postcodes, of which 5,814 fall in Southampton itself, spread across six outward codes from SO14 to SO19.

Signature project

Find any of 5,814 postcodes in about one step

A hash table turns a key, such as a postcode, into a bucket number, so a lookup can jump straight to the right place. We stored every Southampton postcode in 7,919 buckets with two different hash functions.

Storing 5,814 Southampton postcodes in 7,919 buckets
MethodBuckets usedLongest chainComparisons per lookup
Plain list, no hashingNot applicableNot applicable2,907.5 on average
Hash that adds up character codes6122775.6 on average
FNV-1a hash3,90171.45 on average

1. Choose the buckets

Pick a prime number of buckets a little above the number of keys: 7,919 for 5,814 postcodes, a load of about 0.73 keys per bucket.

2. Hash each key

A hash function turns SO17 1BJ into a bucket number. Keys landing in the same bucket are kept in a short list, a chain, and checked one by one.

3. Measure the chains

Count how many buckets each hash actually uses and how long the longest chain grows. That, not how neat the code looks, decides the speed.

Why adding up letters fails

Every Southampton postcode is built from the same small set of characters, so the sum of their character codes only runs from 473 to 536: just 61 possible values. The simple hash therefore crams 5,814 postcodes into 61 buckets, 227 in the worst. It also sends anagrams to the same place every time, and there are 1,417 groups of Southampton postcodes that are rearrangements of each other, such as SO14 0AE and SO14 0EA. FNV-1a mixes every character into the whole result and spreads the same keys over 3,901 buckets.

Even a good hash collides sooner than intuition suggests. With 7,919 buckets, theory says a shared bucket becomes more likely than not after about 105 keys; drawing random Southampton postcodes 20,000 times, the first shared bucket came after a median of 96. FNV-1a also used slightly fewer buckets than a perfectly random hash would, 3,901 against an expected 4,119, a reminder that real hash functions are good rather than perfect on keys as alike as postcodes.

Designing lookups

Five habits for fast, fair lookups

Learned on postcodes, used afterwards on usernames, product codes, caches, databases and the dictionary inside almost every program.

Building a hash table that stays fast
HabitWhat it looks likeWhat it prevents
Know your keysLook at what the keys have in common before choosing a hash; postcodes reuse a tiny alphabetA hash that ignores the structure of its keys
Mix every characterUse a hash in which each character changes the whole result, such as FNV-1aAnagrams and near-duplicates piling into one bucket
Size the table sensiblyKeep the load below about one key per bucket and use a prime bucket countChains that lengthen as the data grows
Measure, do not assumeCount used buckets and the longest chain on the real dataA hash that looks fine on paper and crawls in practice
Plan for collisionsHandle shared buckets from the start, since they arrive after roughly the square root of the bucket countCode that breaks the first time two keys meet

The last habit is the birthday paradox at work. In a room of 23 people, two share a birthday more often than not, and a table of 7,919 buckets sees its first collision after around a hundred keys. Every hash table in every programming language is built to handle that calmly, which is why learners write their own before trusting the built-in one.

Younger learners

Sorting cards into labelled boxes by their first letter, then noticing which box overflows and inventing a fairer rule.

Teenagers

The Code-Point file read in Python, two hash functions written and measured, chains counted and the birthday paradox tested.

Adults

Indexes, caches and lookups at work, with key structure and load factor checked before performance is promised.

We are not connected with Ordnance Survey or the Office for National Statistics. Code-Point Open is published as open data; the tables, hashes and counts are our own work.

Learning ladder

From labelled boxes to a hash table

Use the ages as a rough guide; the free lesson settles the level.

Ages 6 to 10

Sorting into boxes

Filing cards by a simple rule, spotting when one box fills up, and finding a fairer way to share them.

Mental Maths for KidsProblem Solving and Computational Thinking for Kids
Ages 11 to 13

Codes and lookups

Characters as numbers, dictionaries that find things by name, and a first home-made hash.

Python and AI for KidsMaths Through Coding
Ages 14 to 18

Hash tables in Python

Hash functions compared on real keys, chaining and load factor measured, and collisions predicted.

Problem Solving for TeensPython for Teens
Ages 18 to 67

Lookups at scale

Indexes, caching and hashing in databases and services, with performance measured on real data.

Data Structures & Algorithms CourseMySQL Course
Coding and AI

An assistant can look up any postcode. Why should a Southampton teenager build a hash table?

Because the gap between one step and seventy-six is invisible until someone measures it.

Ask an AI tool to write a postcode lookup and it will usually reach for a built-in dictionary, which is the right choice. Ask it to design its own hash, though, and a plausible function that adds up the characters would pass a quick test and then crawl on real data, using 61 buckets out of 7,919. A learner who has measured the chains can catch that in a code review; one who has not will ship it.

Hashing also sits at the heart of modern computing and AI. Databases index records with it, websites cache pages with it, and large AI projects use it to find near-duplicate documents in their training data. One small table of postcodes opens the door to all of those ideas.

So a Southampton teenager should still learn to program in 2026, in the city Ordnance Survey moved to in 1841: software now writes code on request, and knowing which code is quietly slow is exactly what programming teaches. The longer argument is in is learning to code still worth it in 2026.

Delivery

Shirley, Portswood or Bitterne, from home

Whichever side of the Itchen a learner lives on, a live online lesson needs no bridge.

Both banks of the Itchen

A learner in Woolston and another in Freemantle can share one lesson without either crossing the river.

English stages, English names

Reception, the four Key Stages, Year 9 options, GCSEs and A levels, called what Southampton schools call them, and taught in English.

A useful first lesson

The free lesson teaches something real and ends with a recommended level, course and regular weekly time, with no card requested.

Groups set by level

Five to ten learners at one stage, from Southampton, the rest of the UK and abroad, so every level has a slot that works.

Two fixed lessons weekly

The same two times each week, about eight lessons a month, with holiday and exam pauses agreed with the teacher ahead of time.

A fixed clock in India

Our teachers work on India Standard Time, which stays fixed all year, so they are four and a half hours ahead of Southampton in summer and five and a half in winter; after-school and evening lessons sit inside their day.

Across Hampshire too

Families in Eastleigh, Totton or the New Forest join exactly the same groups, because every lesson is online and groups are formed by level rather than postcode.

Fees

Southampton lesson fees

A free first lesson, then one of two prices.

First classUSD 0

A complete lesson with nothing to pay, closing with a level, a course suggestion and a weekly time.

Group tuitionUSD 100

Around eight live lessons a month, in a group of five to ten learners at one level.

Private tuitionUSD 150

Around eight live lessons a month, with the teacher working only with your learner.

All families outside India pay a single US dollar fee, so Highfield and Harefield pay exactly the same, and we list no prices in pounds. Billing starts only after the free lesson has fixed a course and a time; the pricing page explains pauses, missed lessons and changing between group and private teaching.

Reviews

What six families told Google, unedited

Rated 4.9 across 547 Google reviews. These are real reviews, reproduced as written.

★★★★★

"The one step solution for my son. Modern Age Coders make learning coding so simple that kids love it. The teachers explain complex concepts clearly with practical exercises and interactive content."

Ria Mukherjee

Parent

★★★★★

"Modern Age Coders has been a game-changer for me. I struggled to grasp IT concepts and coding before joining, but their classes transformed everything. I can now confidently write complex programs with ease."

Samriddha Mondal

Student

★★★★★

"One of the most wonderful education centres out there. Education is not limited to school syllabus but focuses on skill development."

Vansh Agarwal

Student

★★★★★

"My child Dhairya is really enjoying the Modern Age Coders classes. This is his first online class and he eagerly looks forward to it. I can already see his improvement, and the teachers are very cooperative."

Sonam Oswal

Parent of Dhairya

★★★★★

"Modern Age Coders have wonderful teachers who teach in a clear, easy and practical way. The teacher boosts students' confidence and inspires them to learn without hesitation."

Sonu Goyal

Parent

★★★★★

"I highly recommend this computer coding class! The teachers are incredibly knowledgeable and passionate about coding."

Ritu Kedia

Parent

Free placement class

Book a free lesson for a Southampton learner

We pick the first task by level: sorting cards into boxes for a young child, a first Python dictionary for a middle-schooler, or the Code-Point file and two hash functions for a teenager ready for real data.

+44

FAQ

Southampton coding class questions

What Southampton families ask us most.

How many people live in Southampton?

The 2021 Census counted 248,922 usual residents in the Southampton local authority: 238,765 in households and 10,157, or 4.1%, in communal establishments.

How many Southampton residents are students?

In 2021, 60,197 of the 235,126 residents aged five and over were schoolchildren or full-time students, 25.6% against 20.4% in England.

Why is Ordnance Survey linked with Southampton?

Ordnance Survey says a fire at its Tower of London offices in 1841 prompted a move to a new Southampton headquarters. Its head office today, Explorer House, has a Southampton postal address. We are not connected with Ordnance Survey.

What is a hash table?

A way of storing data so that a key, such as a postcode, is turned by a hash function into a bucket number, letting a program find it in about one step instead of searching a whole list.

Why does adding up the letters make a bad hash?

Because Southampton postcodes share so few characters that the sums take only 61 different values, so 5,814 postcodes crowd into 61 buckets, and anagrams such as SO14 0AE and SO14 0EA always collide.

How many postcodes does Southampton have?

Ordnance Survey's Code-Point Open, version 2026.3.0, lists 5,814 postcodes in the Southampton local authority, across the outward codes SO14 to SO19.

When are Southampton lessons?

Weekday afternoons and evenings or weekends, at a UK time agreed during the free lesson. Our teachers are four and a half hours ahead of Southampton in summer and five and a half in winter.

Is there a Modern Age Coders centre in Southampton?

No. We have no Southampton centre and no premises anywhere in the UK; every lesson runs live online. Learners need a computer with sound and a steady connection, and our phone number is based in India.

How much do Southampton lessons cost?

The first lesson is free. After that a group place is USD 100 a month for two live lessons a week, about eight a month, with five to ten learners, and one-to-one lessons on the same schedule are USD 150 a month. Course, format and time are agreed before anything is charged.

How are Southampton groups formed?

By ability, pace and aims rather than age or postcode, with five to ten learners at one level. If no group meets at a suitable time, we offer one-to-one lessons.

Explore the UK

Southern cities and the national guide

To the west, the Bristol page splits its city into library catchments with a Voronoi diagram, and to the north Oxford builds a Markov chain from two centuries of rain. London has a guide of its own. The England guide explains the school stages, and every UK page is linked from the UK coding page.

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