A PER simulator is an online calculation tool that projects the evolution of retirement savings based on personalized parameters: income, contributions, investment duration, and marginal tax rate. Its role is to quantify two distinct outcomes: the capital accumulated at retirement and the tax savings generated by each deductible contribution. Understanding what this tool actually produces helps avoid decisions based on overly vague estimates.
Deferral of PER deduction limits: the parameter that most simulators ignore
The 2026 finance law has extended the deferral of retirement savings limits from 3 to 5 years for rights accrued from January 1, 2026. This change alters how a simulator should calculate the available deductible contribution margin.
Specifically, if a saver has not reached their annual deduction limit in previous years, they can now recover up to five years of unused rights instead of three. For a couple, the strategy of pooling limits between spouses becomes even more flexible.
A simulator that does not incorporate this 5-year extension underestimates the capacity for deductible contributions. Before launching a simulation, it is essential to check that the tool allows for the selection of the year of the consumed limit. Not all free tools available online have yet integrated this update, and using Finance Factory’s return on investment simulator provides projections that take these recent developments into account.
To utilize this data, simply consult the tax notice from the previous year: the available limit is listed in the section dedicated to retirement savings. This value should be entered in the corresponding field of the simulator.
Input variables of a PER simulator: what to enter and in what order
The reliability of a simulation entirely depends on the quality of the data entered. Three categories of variables determine the outcome.
- Income and marginal tax rate (TMI): the TMI determines the amount of tax savings. A contribution of the same amount does not yield the same tax benefit depending on whether the saver is in a 30% or 41% bracket. Some simulators automatically calculate the TMI based on net taxable income and the number of tax shares, while others require manual entry.
- Amount and frequency of contributions: a regular monthly contribution and a one-time annual contribution do not produce exactly the same final capital due to the mechanism of compound interest. A serious simulator distinguishes between these two rhythms.
- Investment horizon and retirement age: the remaining time before retirement determines the number of years of capitalization. The longer the horizon, the more the effect of compound interest amplifies the capital. The age should correspond to the actual planned retirement age, not a default age set by the tool.
Entering these variables in this order (taxation, then contributions, then horizon) avoids the need to restart the simulation with each correction.
PER taxation at withdrawal: simulating the real cost of capital or annuity release
The tax advantage at entry is only one side of the calculation. At the time of withdrawal, the capital or annuity is subject to taxation, the weight of which depends on the chosen exit method and the TMI at retirement.
In capital withdrawal, the portion corresponding to the deducted contributions is re-taxed at the income tax scale. Gains (capital gains) are subject to the flat tax. In life annuity withdrawal, the taxable portion of the annuity depends on the age at the time of conversion.
A simulator that only displays the tax savings at entry provides a skewed view. The tool must also project the taxation at withdrawal to calculate the actual net gain. This distinction between gross benefit and net benefit is the main quality criterion of a PER simulator.
Typical scenario for comparison
Running two parallel simulations helps to decide: one 100% capital withdrawal and one mixed (partial capital plus annuity). By comparing the net amount after tax in each case, the saver can adjust their contribution strategy in advance rather than facing taxation at the time of withdrawal.
End of deductibility after 70 years: a limit to integrate from the first simulation
As of January 1, 2026, voluntary contributions made to a PER after the account holder’s 70th birthday are no longer deductible from taxable income. This change removes the tax interest of late contributions and alters the useful duration of simulation.
For a 55-year-old saver, the deductibility horizon remains 15 years. For a 65-year-old saver, only 5 years of tax-advantaged contributions remain. The simulation must reflect this limit: projecting deductible contributions beyond 70 years would distort the estimation of the total tax advantage.
This parameter also has an indirect effect on the managed investment offered by some PERs. The gradual securing of the portfolio, which reduces exposure to equities as retirement approaches, must be calibrated according to this shortened deductibility horizon, not just the retirement age.
Limitations of an online PER simulator: what the tool does not calculate
No free simulator replaces a complete wealth analysis. Several elements remain outside the standard calculation scope.
- The actual costs of the PER contract (contribution fees, annual management fees, switching fees) vary significantly from one contract to another and reduce net returns. Few simulators incorporate these fees into the projection.
- The impact on other tax schemes (capping of tax niches, interaction with existing tax reductions) is generally not modeled.
- The future performance of investment supports is hypothetical, based on average historical returns. A displayed annual return rate does not constitute a guarantee.
The simulator provides an order of magnitude, not a contractual commitment. The displayed results remain projections that depend on volatile parameters. Comparing the results of several different simulators, while keeping the same starting assumptions, allows for identifying methodological discrepancies and obtaining a more realistic range than the result of a single tool.