How this calculator is built
Built by an Australian Chartered Accountant— the same engine the paid NestWise dashboard runs. Every rate table is verified against the source below every 1 July, 20 March, and 20 September and covered by a 200+ scenario regression suite.
How Family Tax Benefit is calculated
Family Tax Benefit has TWO parts that work independently. Most families qualify for one, some for both. The calculator above runs both at once.
FTB Part A
Paid per child. The amount depends on the child’s age (under 13 vs 13-19) and your combined family income. Up to the lower income free area you get the maximum rate; above that, the payment tapers down. Two tapers apply: 20c per dollar over the lower free area, then 30c per dollar above the higher free area.
FTB Part B
Paid per family, designed for single-income or low-secondary-income households. The primary earner’s income must be below a threshold (currently around $124,327); above that, no Part B. If you qualify, the secondary earner’s income tapers Part B down at 20c per dollar over a low free area. Eligibility also depends on the age of your youngest child (cuts off at 13 for couples, 18 for single parents).
The $80,000 FTB-A supplement — the thing most calculators miss
End of every financial year, families on FTB-A who got at least one fortnightly payment and stayed BELOW $80,000 combined ATI receive an annual supplement of approximately $971 per child. It’s paid after EOFY reconciliation (usually August/September) once the ATO confirms your actual income.
The cliff: $80,000 ATI is a HARD CUT-OFF, not a taper. A family on $79,500 with two kids gets ~$1,876 in supplements at EOFY. A family on $80,500 with the same two kids gets $0. Crossing the $80,000 line by $1 costs ~$971 per child.
The calculator above factors this in. Many other AU calculators (and Centrelink’s own pre-recon estimate) leave it out of the annual figure they show, because it’s a post-EOFY payment. The full annual amount your family receives includes the supplement — we’d rather you see the real number.
Why this matters for decisions
If you’re considering an extra day of work or a bonus that pushes you over $80,000, run the calculator at both incomes. The marginal cost of crossing the cliff is real money. Some families decide to salary-sacrifice the difference to super to stay under — not advice, but the maths is visible to you here.
Worked example: the Patel family
Raj and Anjali Patel have two kids: Aarav (age 8) and Diya (age 5). Combined family income $76,000 (Raj earns $50k, Anjali $26k). Both partnered. Living in Sydney, renting privately at $580/week.
FTB Part A
At $76,000 they’re ABOVE the $69,131 lower free area, so the taper kicks in. The engine applies the FTB-A formula (max rate × kids minus 20c per dollar over the free area, with the upper threshold step) and lands on roughly ~$10,913/year FTB-A before the EOFY supplement. (Numbers computed live by the same engine the calculator uses.)
FTB Part B
Anjali is the secondary earner at $26,000. The Part B secondary-earner free area is $7,154; she’s well over it, so the taper applies. Engine output for the household: ~$0/year Part B.
EOFY supplement
Combined ATI $76,000 — UNDER the $80,000 cliff. Both kids qualify for the ~$971 supplement = ~$1,942 at EOFY.
Total annual entitlement
Part A ($10,913) + Part B ($0) + EOFY supplement ($1,942) = ~$12,855/year.
(Also potentially eligible for Rent Assistance on top of Part A — run the rent-assistance figures separately if private renting.)
Plug the Patels’ numbers (or your own) into the calculator above — the supplement is included in the annual total automatically.
How NestWise compares to the Services Australia calculator
Services Australia’s Payment and Service Finder estimates FTB-A and FTB-B from your income + children. The NestWise calculator implements the same formula with rates source-traced to the same Services Australia rate tables. Where we differ is the EOFY supplement — we include it; the official pre-recon estimator typically doesn’t.
What NestWise surfaces that other tools don’t
- The full annual number including the EOFY supplement. So the figure you see is what your family actually receives across the year.
- The $80,000 cliff explicit. If you’re close to it, we surface that — cross it by $1 and the supplement disappears.
- Part A + Part B in one view. Many calculators run one or the other; we run both.
- Live recalc. Tweak income, change youngest age, switch partner status — figures move on every keystroke.
What NestWise doesn’t model in this free calc
- Maintenance Income Test — if you receive child support, that reduces FTB-A above the disregard. The full NestWise dashboard handles this; the free calculator assumes no child-support received.
- Shared-care percentages — if your children are in shared care, FTB is split proportionally. Use the full dashboard surface for the per-percentage breakdown.
- Rent Assistance on top of FTB-A — calculated separately; not in this calc’s annual figure.
- Income from non-residents, foreign pensions, exempt income — standard rules; talk to Services Australia for edge cases.
Five common mistakes when estimating FTB
- Missing the EOFY supplement in your annual figure. If you’re under $80,000 and on FTB-A, the supplement is real money — ~$971 per child per year, paid in August/September. Many calcs omit it.
- Crossing the $80,000 cliff without realising. The supplement is a hard cut-off, not a taper. The calculator above tells you if you’re close so a small income decision doesn’t cost you the supplement.
- Forgetting Part B has a youngest-age cutoff. 13 for couples (i.e. youngest child must be under 13), 18 for single parents. Once your youngest crosses, Part B stops — even if you’ve been receiving it for years.
- Using gross household income instead of ATI. FTB uses Adjusted Taxable Income (taxable income + reportable super + investment losses + reportable fringe benefits + foreign income). Most families think it’s just taxable; ATI can be meaningfully higher.
- Not updating your estimate when income changes. If your actual income ends up materially different from what you told Centrelink, you’ll owe a debt (or be owed a top-up) at recon. Update your estimate via myGov when income shifts.
When to re-estimate your FTB
Rates re-index 1 July annually. Beyond that, re-run the calculator when:
- Income changes by $5,000 or more — especially if it puts you near the $80,000 supplement cliff.
- A child has a birthday at 13 or 19. Part A rate steps at 13; Part B eligibility ends when youngest hits 13 (couples) or 18 (singles); FTB ends entirely at 19.
- Relationship status changes. Single ↔ couple flips the Part B test completely.
- You start or stop receiving child support. Maintenance Income Test reduces FTB-A above the disregard — switch to the full dashboard for the MIT-aware figure.
- You start salary-sacrificing. Reportable super lifts your ATI even though your take-home looks the same — can push you over thresholds.
Run the calculator above with your new numbers, then read the full FTB guide and update your estimate via myGov → Centrelink → Family Assistance.
Related reading
The full Family Tax Benefit picture in plain English.
Family Tax Benefit Part A — how much will I get in 2026-27? →
A clear breakdown of FTB Part A for 2026-27 — what each child is worth per fortnight, how the income test tapers the rate, and the end-of-year supplement that catches families out.
Family Tax Benefit Part B — the $124,327 cliff explained (2026-27) →
FTB Part B in 2026-27 — the $124,327 primary earner cap, the secondary earner taper, how much per child, and why single-income families benefit most. Verified rates.
The FTB-CCS debt trap — how one income mistake causes two Centrelink debts →
Both CCS and FTB are paid on your income estimate and reconciled at tax time. A single underestimate triggers debts on both — often thousands of dollars. Here's why it happens and exactly how to avoid it.
Newborn Supplement & Upfront Payment 2026-27 — what you actually get →
The Newborn Upfront Payment ($683) and Newborn Supplement (up to $2,052 over 13 weeks) explained — eligibility, how PPL affects it, and when each lands in your account.