How much can I get into Roth this year? Drop a single script tag into your site, then use <retirement-calc-backdoor> as a custom HTML element anywhere on the page. Consolidates 3 strategies under one composite question: direct Roth IRA, Backdoor Roth IRA, and Mega Backdoor Roth. Eligibility status + dollar room for each, plus pro-rata warnings + plan-allows checks.
Composes with <retirement-calc-irmaa> (Medicare surcharge cliff) and <retirement-calc-roth> (Roth conversion sweet spot) as the Roth-strategies discovery trio.
Pick colors that match your site, then copy the CSS snippet at the bottom.
retirement-calc-backdoor {
--rc-accent: #4f8ec9;
--rc-bg: #ffffff;
--rc-surf: #f7f9fc;
--rc-text: #1a1f2e;
}Drop this into your HTML:
<script src="https://app.retirementscenario.com/embed/v1/backdoor.js"></script>
<retirement-calc-backdoor></retirement-calc-backdoor>Or pre-seed values relevant to your audience:
<retirement-calc-backdoor
plan-type="household"
current-age="45"
annual-magi="300000"
current-401k="24500"
employer-match="20000"
existing-trad-ira="0"
plan-allows-mega="yes">
</retirement-calc-backdoor>| Attribute | Default | Range |
|---|---|---|
plan-type | household | single or household (= MFJ — affects MAGI phase-out threshold) |
current-age | 45 | 25 – 70 (≥50 enables IRA catch-up + 401(k) catch-up; 60-63 enables SECURE 2.0 super catch-up) |
annual-magi | 300000 | 30,000 – 500,000 (household combined modified AGI) |
current-401k | 24500 | 0 – 35,750 (your employee 401(k) deferral this year) |
employer-match | 20000 | 0 – 50,000 (annual employer match contribution) |
existing-trad-ira | 0 | 0 – 1,000,000 (pre-tax Trad IRA balance — triggers pro-rata warning) |
plan-allows-mega | yes | yes or no (does your 401(k) support after-tax + Roth conversion?) |
refsrc | (none) | partner attribution tag |
Honest scope: 2026 IRS limits (refresh annually with the engine's IRS-limits refresh slice). Models USER's IRA only — for HH plans, the spouse can do the same backdoor strategy independently (effectively doubling the total). Mega Backdoor room is calculated from YOUR plan; spouse's plan has its own separate 415(c) room. Pro-rata rule warning is informational — doesn't compute the actual tax bill (depends on marginal rate). Doesn't model 415(c) reductions for other employer contributions (profit-sharing, etc.) beyond direct match. For multi-year contribution planning + plan modeling, use the full app.
Override CSS custom properties on the host:
retirement-calc-backdoor {
--rc-accent: #ff6b35; /* primary color */
--rc-bg: #ffffff; /* card background */
--rc-surf: #f7f9fc; /* sub-surface (result area) */
--rc-text: #1a1f2e;
--rc-muted: #6a7280;
--rc-border: rgba(20,30,50,0.10);
--rc-radius: 12px;
}The element emits two custom events you can listen to:
document.querySelector('retirement-calc-backdoor')
.addEventListener('rc-calculated', (e) => {
console.log('Total Roth potential:', e.detail.totalRoth); // $ across all 3 strategies
console.log('Direct Roth IRA:', e.detail.directRoth); // { limit, status: 'full'|'partial'|'phased_out', phaseoutLow, phaseoutHigh }
console.log('Backdoor Roth IRA:', e.detail.backdoorRoth); // { limit, proRataPct, proRataWarning, existingTradIra }
console.log('Mega Backdoor:', e.detail.megaBackdoor); // { limit, room, status: 'available'|'plan_doesnt_allow'|'no_room', cap415c }
});
document.querySelector('retirement-calc-backdoor')
.addEventListener('rc-cta-clicked', (e) => {
console.log('User clicked CTA to:', e.detail.url);
});