Example · Urban SA household
Net household income
R 35,000
After PAYE, UIF and standard deductions
Explainer: Hidden Cost Model
The Hidden Cost Index groups “system failure costs” into six buckets and shows how much they erode your income before you ever get to lifestyle. This panel explains the logic. The next tabs let you run your own numbers and compare cities.
Hidden cost total
R 11,800
Security, load shedding, medical aid, transport, crime, education
Shadow tax rate
31%
Hidden costs as share of gross income
True disposable income
R 23,200
What is actually left to live on
How the model treats your money
Gross income
→
Tax & statutory deductions
→
Net income
→
Hidden costs (system failure)
→
True disposable income
Hidden cost categories
Hidden costs are recurring monthly amounts paid not to improve your lifestyle, but to replace basic infrastructure, safety and services that should exist by default in a functioning system.
Security tax
Armed response, electric fencing, cameras, guard levies and crime-loaded insurance premiums.
Infrastructure failure
Inverters, batteries, generators, backup fibre/LTE, water storage and surge-damaged appliances.
Health system gap
Medical aid, gap cover and out-of-pocket healthcare spend because the public system is not reliable.
Transport penalty
Car instalments, fuel, maintenance and insurance where public transport is not a safe or usable default.
Education uplift
Private or semi-private school fees and extra lessons where public schools are not realistically viable.
Crime & risk premium
Higher excesses, recurring loss and self-insurance for theft and damage that are structurally priced in.
What the dashboard calculates
Hidden Cost Total – R/month across all categories
Shadow Tax Rate – hidden cost as % of gross income
True Disposable Income – net income minus hidden cost
Hidden Cost Index (HCI) – hidden cost vs basic cost-of-living
Move to Tab 2 to enter your own numbers, or Tab 3 to compare cities and scenarios.
Hidden Cost Calculator
Enter your monthly numbers below. The model will estimate your hidden cost total, the shadow tax rate, your true disposable income, and a simple Hidden Cost Index. All amounts are in South African Rand (R).
Before PAYE and deductions. Used to compute the shadow tax.
If left blank, we estimate ~75% of gross.
Used as the denominator for the Hidden Cost Index (HCI).
Hidden cost categories – monthly spend to “patch the system”, not to upgrade your lifestyle.
The dashboard updates automatically as you type. If a field doesn’t apply, leave it on zero.
Results
These metrics are computed from your inputs. They do not judge how you spend; they show how much is being forced into system failure rather than actual living.
Hidden cost total
Sum of security, infrastructure, health, transport, education, crime
Shadow tax rate
0%
Hidden costs ÷ gross income
True disposable income
R 0
Net income minus hidden cost
Hidden Cost Index (HCI)
0
Hidden cost ÷ basic life cost (rent + food + utilities)
How to read this
Shadow Tax Rate > 25% – a sizeable share of gross income is going to system failure.
HCI ≈ 50 – hidden costs equal half of your basic cost-of-living.
HCI ≥ 100 – hidden costs match or exceed your core life expenses.
These are descriptive, not prescriptive. The point is not to tell you what to cut, but to show you how much of your income is functioning as an invisible survival tax.
City comparison
Four stylised scenarios: Johannesburg, Cape Town, Melbourne and Shenzhen. Each profile uses typical income, basic life cost and hidden cost assumptions to show how hard the system leans on households.
Hidden Cost Index (HCI)
–
Johannesburg · Hidden cost ÷ basic life cost
HCI – Cape Town
–
Cape Town · higher rent, similar hidden cost structure
HCI – Melbourne
–
Melbourne · high core cost, lower hidden system failure cost
HCI – Shenzhen
–
Shenzhen · low security / infra cost, high savings potential
Scenario assumptions
These are simple, illustrative profiles. They are not personalised budgets. The goal is to show relative pressure from hidden costs, not exact household finances.
Johannesburg
Mid-income, car-dependent, typical security setup
Net income–
Basic cost–
Hidden cost
True disposable–
Cape Town
Higher rent, similar risk profile, similar medical burden
Net income–
Basic cost–
Hidden cost
True disposable–
Melbourne
High basic cost, low security and infra failure
Net income–
Basic cost–
Hidden cost
True disposable–
Shenzhen
Teacher scenario: high net income, low security / infra burden
Net income–
Basic cost–
Hidden cost
True disposable–
In a later version, these profiles can be driven from live or API-fed baseline data per city (fuel prices, rent indices, crime stats, load shedding severity and medical inflation).