Both are UK-focused financial tools, but they serve different needs. Isaac is a retirement calculator. Delphina is comprehensive financial planning that connects your daily finances to your long-term goals.
Isaac is a focused retirement planning tool. It helps you understand your pension projections, model different retirement ages, and see year-by-year forecasts to age 100. It's well-designed for what it does.
Delphina connects daily budgeting, expense tracking, and long-term retirement planning in one platform. For people who want to see how their spending today affects their retirement tomorrow.
Isaac shows your projection. Delphina shows whether that projection supports the retirement you actually want — and what to change if it doesn't.
Get my verdictBased on publicly available information from both services.
| Feature | Isaac | Delphina |
|---|---|---|
| Free Tier Available | ✓ | ✓ |
| Retirement Projections | ✓ | ✓ |
| Year-by-Year Forecasting to Age 100 | ✓ | ✓ |
| Scenario Modelling | ✓ | ✓ |
| UK Tax Calculations | ✓ | ✓ |
| Couple Planning | ✓ | ✓ |
| Monte Carlo Simulations | Limited | ✓ (10,000 iterations) |
| Daily Budgeting & Expense Tracking | ✗ | ✓ |
| Open Banking Integration | ✗ | ✓ |
| Human Financial Coaching | ✗ | ✓ |
| Net Worth + Cash Flow Combined | ✗ | ✓ |
| FIRE-Specific Calculations (Coast FI, Barista FI) | ✗ | ✓ |
| Pricing | Free / £7.99/mo | Free / From £9.99/mo |
Isaac gives you a retirement number. Delphina gives you a verdict on whether that number supports the future you actually want — and what to change if it doesn't.
"Isaac gave me a number. Delphina told me whether that number was actually enough — and what to change to make it so. Same data, very different answer."
Trusted by
12,000+ UK households
planning their financial future with Delphina
If you want a focused retirement calculator, Isaac is solid. If you want to connect your daily finances, budgeting, and long-term retirement planning in one place, Delphina is there.
See how Delphina connects your daily spending habits to your retirement projections.
Isaac focuses on retirement. Delphina includes daily budgeting alongside retirement planning.
UK-specific FIRE calculations including Coast FI, Fat FI, and Barista FI strategies.
Isaac is a focused retirement planning tool. It does one thing well: pension projections and scenario modelling. The interface is clean, and the retirement focus means less complexity.
Delphina connects your daily finances to your retirement. Budgeting, spending tracking, investments, and long-term planning in one place. More comprehensive, but requires more setup.
Year-by-year projections to 100, multiple scenarios, couple planning, and drawdown strategy modelling. Strong for pure retirement income planning.
Monte Carlo simulations with 10,000 iterations, probabilistic success rates, and stress testing. Real-time net worth that updates with your actual spending. FIRE-specific calculations.
Free tier available. Premium at £7.99/month. Excellent value for a focused retirement calculator.
Free tier available. Premium from £9.99/month. Includes daily budgeting, open banking, and coaching. Price reflects the broader feature set.
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Isaac has a free tier with basic features. Premium is £7.99/month. It's genuinely useful for what it does.
Isaac models pensions, ISAs, property, and other assets in retirement projections. Delphina integrates investment tracking with daily budgeting and real-time net worth updates via open banking.
Yes. Delphina provides UK-focused planning including state pension projections, UK tax bands, ISA allowances, and pension contribution limits.
You could, but it depends on your needs. If Isaac covers what you need for retirement, that's valid. If you want everything connected to daily finances, Delphina is more complete.