Increasing your pension contribution by just 1% of salary feels insignificant. But over a 30-year career, that small change can add £50,000+ to your retirement pot thanks to compound growth and tax relief. And the monthly cost to your take-home pay is far less than 1% of your salary.
The real cost of 1% more
On a £40,000 salary, 1% is £400/year or £33/month gross. But thanks to tax relief and NI savings (via salary sacrifice), the actual reduction in your monthly take-home is approximately:
- Basic rate taxpayer: ~£24/month (you save 28% in tax+NI)
- Higher rate taxpayer: ~£19/month (you save 42% in tax+NI)
That is less than the cost of a streaming subscription — for a benefit worth tens of thousands at retirement.
The compounding effect
£400/year invested at 5% real growth for 30 years grows to approximately £27,000 in today's money. If your employer matches the increase (common in many schemes), that doubles to £54,000. And this is from a change you barely notice in your pay packet.
When does the 1% go in?
Every year you delay costs you. Starting the extra 1% at age 25 vs. age 35 (same retirement age of 57) gives you 10 additional years of compounding — roughly 60% more in the pot by retirement.
Stacking increases over time
A powerful strategy: increase your contribution by 1% every year when you receive your annual pay rise. Your net pay never actually decreases year-on-year (the raise covers the increase), but your pension snowballs:
- Year 1: 5% contribution
- Year 2: 6% contribution
- Year 3: 7% contribution
- By Year 10: 15% contribution — with no reduction in take-home vs. Day 1
Model the impact yourself
Use the salary sacrifice calculator to see how a 1% increase affects your monthly take-home today. Then use the pension tax relief calculator to see the tax relief boost applied to your contribution.