How to Calculate WFH Deductions: 3 Australian Scenarios

Most Australians who work from home default to the Australian Taxation Office (ATO) Revised Fixed Rate Method (67 cents per hour) simply because multiplying hours by 67 cents feels easy at tax time. Yet for anyone who uses a personal mobile phone and home NBN plan regularly for work, the fixed rate's bundling rule can quietly cost hundreds of dollars in lost deductions every year.

To make the comparison instant, we built the free, in-browser ATO Working From Home (WFH) Deduction Calculator. Below, we walk through three realistic Australian working-from-home profiles to show when the Fixed Rate Method wins, when the Actual Cost Method pulls ahead, and what records you need to keep for each (the full eligibility and substantiation rules are in our WFH deductions guide).

Why the Two Methods Produce Very Different Totals

The core trade-off between the two methods comes down to what gets bundled:

• Under the Fixed Rate Method (67c/hr), your hourly claim already absorbs mobile phone usage, home internet, household electricity and gas, and computer consumables/stationery. You cannot claim any of those items separately anywhere else on your tax return.
• Under the Actual Cost Method, you calculate and claim the work-related percentage of your mobile phone bill, home internet bill, workspace heating/cooling/lighting power, and stationery individually based on bills and a four-week representative usage diary.

Both methods still allow you to claim a separate deduction for the decline in value (depreciation) of work equipment and office furniture (such as a laptop, monitor, or ergonomic chair)—or an immediate deduction for work items costing $300 or less.

Feature	Scenario A: Hybrid Mobile-Heavy	Scenario B: 5-Day Remote Engineer	Scenario C: 1-Day WFH Low Bills
WFH schedule	2 days/wk (768 hrs/yr)	5 days/wk (1,920 hrs/yr)	1 day/wk (384 hrs/yr)
Mobile bill & work use %	$85/mo at 50% work	$55/mo at 20% work	$40/mo at 10% work
Home NBN bill & work use %	$90/mo at 30% work	$100/mo at 40% work	$80/mo at 15% work
Apportioned power & stationery	$180/yr	$480/yr	$75/yr
Higher-deduction method	Actual Cost ($1,014 vs $515)	Fixed Rate ($1,286 vs $1,092)	Fixed Rate ($257 vs $267 — near tie)

Scenario A: The Hybrid Professional With High Mobile Usage

Sam works in project management, spending 3 days in the CBD office and 2 days working from home (16 hours/week across 48 working weeks = 768 WFH hours/year). Because Sam coordinates site contractors and client calls on a personal mobile phone all week, a four-week diary shows 50% work use on an $85/month mobile plan and 30% work use on a $90/month home NBN plan, plus $180/year in apportioned workspace electricity and printer consumables.

• Fixed Rate Method: 768 hours × $0.67 = $514.56 (and $0 separate phone or internet claim allowed).
• Actual Cost Method: $510 (mobile) + $324 (internet) + $180 (electricity & consumables) = $1,014.00.

By keeping monthly phone and internet invoices plus a 4-week diary, Sam's legitimate deduction is $499.44 higher under the Actual Cost Method. At a 32% marginal tax rate (including Medicare levy), that is an extra $160 in tax saved.

Scenario B: The Full-Time Remote Software Engineer

Priya works from home 5 days a week (40 hours/week × 48 weeks = 1,920 WFH hours/year). Almost all communication happens over Slack and Zoom on a work-supplied laptop, so her personal mobile phone work use is only 20% on a $55/month plan ($132/year), alongside 40% work use on a $100/month NBN plan ($480/year) and $480/year in workspace power and consumables.

• Fixed Rate Method: 1,920 hours × $0.67 = $1,286.40.
• Actual Cost Method: $132 (mobile) + $480 (internet) + $480 (power & consumables) = $1,092.00.

Plus, because Priya bought a $280 monitor arm and a $1,800 ergonomic desk/chair setup, she can still claim immediate write-off ($280) and depreciation on top of the $1,286.40 Fixed Rate claim!

1. Scenario B (5-day remote) — Fixed Rate Method$1,286
2. Scenario B (5-day remote) — Actual Cost Method$1,092
3. Scenario A (2-day hybrid, high mobile) — Actual Cost Method$1,014
4. Scenario A (2-day hybrid, high mobile) — Fixed Rate Method$515

Scenario C: One Day a Week From Home With Modest Bills

Liam works from home 1 day a week (8 hours/week × 48 weeks = 384 WFH hours/year), with 10% work use on a $40/month mobile plan ($48/year), 15% work use on an $80/month internet plan ($144/year), and $75/year in electricity.

Here, the Fixed Rate Method ($257.28) and Actual Cost Method ($267.00) are within $10 of each other—making the Fixed Rate Method far simpler so long as Liam keeps his timesheet hours log and one electricity and internet bill.

How to Run Your Own Numbers in 60 Seconds

1. 1. Test your hours and bills in the WFH Deduction Calculator

   Open the free WFH Deduction Calculator at /tools/wfh-deduction-calculator/ and enter your weekly WFH hours, mobile bill, and NBN bill.

2. 2. Keep a contemporaneous hours log all year

   Record your WFH hours in your timesheet, roster, or calendar as you work—the ATO does not accept a 4-week estimate for the Fixed Rate Method.

3. 3. Store your utility, phone, and equipment receipts in PFinance

   Upload your bills and equipment tax invoices via the Receipt Scanner and tag them under D5 Home Office in the Tax Deduction Tracker.

To see which method wins for your schedule, open the ATO Working From Home Deduction Calculator, or combine your deduction estimate with your salary in the Australian Salary Calculator.