How Starlink Pro Rata Billing Works in Australia

Understand exactly how Starlink calculates charges when you upgrade or downgrade plans mid-cycle — with real Australian dollar examples and a comprehensive calculator.

Last updated: March 2026

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Thinking about switching your Starlink plan but not sure what it’ll actually cost? You’re not alone — pro-rata billing is a common question in the Starlink Mini Users Australia Facebook group.

Starlink doesn’t charge you the full price of a new plan when you switch mid-cycle. Instead, they calculate a pro-rata amount based on how many days are left in your billing period. This guide explains exactly how that calculation works, walks through real examples with Australian pricing, and links to our comprehensive calculator so you can check your own numbers before you switch.

In a hurry? Jump straight to the Plan Change Calculator and get your estimate in seconds.

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What Is Pro Rata Billing?

Pro rata simply means “in proportion.” When you upgrade your Starlink plan partway through a billing cycle, Starlink only charges you for the portion of the month you’ll actually use the new plan.

Think of it like rent. If you move into a more expensive apartment on the 15th of the month, you wouldn’t pay the full month’s rent — just the difference for the days remaining. Starlink works the same way.

The key thing to understand: pro-rata charges only apply when you upgrade and choose to switch immediately. If you upgrade but choose to switch at your next billing date, or if you downgrade, there’s no pro-rata charge. More on that below.

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How Starlink Calculates the Charge

Starlink uses a straightforward formula, but there are a couple of quirks worth knowing about.

The Formula

When you upgrade mid-cycle, Starlink calculates:

1. Your new plan’s daily rate = floor(new plan price ÷ 30)
2. Your old plan’s daily rate = floor(old plan price ÷ 30)
3. The difference per day = new daily rate − old daily rate
4. Your charge = difference per day × days remaining in your billing cycle

Two important details:

• Starlink always divides by 30 — regardless of whether the actual month has 28, 30, or 31 days. This keeps the daily rate consistent.
• The floor function rounds down on each daily rate before calculating the total. So $195 ÷ 30 = $6.50, but Starlink floors this to $6/day. This slightly reduces your charge.

A Real Example: Upgrading from 100GB to Unlimited

Let’s say you’re on Starlink Roam 100GB ($80/month) and want to upgrade to Roam Unlimited ($195/month). Your billing date is the 5th, and today is the 20th — so you have 15 days remaining.

Here’s the calculation:

• Unlimited daily rate: floor($195 ÷ 30) = $6/day
• 100GB daily rate: floor($80 ÷ 30) = $2/day
• Difference: $6 − $2 = $4/day
• 15 days remaining: $4 × 15 = $60 pro-rata charge

So you’d pay $60 to upgrade immediately, and your Unlimited plan kicks in straight away. At your next billing date, you’d pay the full $195 for the new cycle.

We verified this formula against actual Starlink invoices — it matches to the dollar.

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Upgrades vs Downgrades: The Key Difference

This trips up a lot of people, so it’s worth being clear. Upgrades and downgrades work differently — and upgrades themselves give you a choice.

Upgrades (Moving to a More Expensive Plan)

When upgrading, Starlink gives you two options:

Switch Now:

• Takes effect immediately
• You pay the pro-rata difference for the remaining days in your current cycle
• Your new plan kicks in straight away

Switch Later (at your billing anniversary):

• Takes effect at the start of your next billing cycle
• No pro-rata charge — you simply pay the new plan price from your next billing date
• You stay on your current plan until then

This is a genuine choice Starlink presents in the app and on the website. If you’re only a few days from your billing date, switching later can save you the pro-rata cost entirely. If you need the upgrade right now — say you’ve hit your 100GB cap and need full speed back — switching immediately is the way to go.

Examples: Standby → 100GB, Standby → Unlimited, 100GB → Unlimited

Downgrades (Moving to a Cheaper Plan)

• No immediate charge
• Your current plan stays active until your next billing date
• The cheaper plan kicks in at the start of your next billing cycle
• You can cancel the pending downgrade if you change your mind
• Examples: Unlimited → 100GB, 100GB → Standby, Unlimited → Standby

This means downgrades are essentially free to schedule — you’ve already paid for the current month, so you keep full access until it expires. Set a reminder a day or two before your billing date if you want to downgrade.

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Common Plan Change Scenarios

Here are the most common switches Australian travellers make, with real dollar amounts at different points in the billing cycle. All figures below assume you choose “Switch Now” — if you choose “Switch Later,” there’s no pro-rata charge and you simply pay the new plan price from your next billing date.

Standby ($8.50) → Roam 100GB ($80)

The classic “trip is starting” upgrade. You’ve been on Standby between trips and now you need proper internet.

Days Remaining	Pro-Rata Charge	Scenario
25 days	$50	Upgrading near the start of your cycle
15 days	$30	Mid-cycle upgrade
5 days	$10	Late-cycle — short trip before billing resets

Tip: You get the full 100GB allowance regardless of when you activate. Upgrading with 5 days left means 100GB for just $10 — then $80 for the full next month.

Roam 100GB ($80) → Roam Unlimited ($195)

The “I’ve burned through my data” upgrade. You hit the 100GB cap and need full speed back.

Days Remaining	Pro-Rata Charge	Scenario
25 days	$100	Early in the cycle — heavy usage month
15 days	$60	Mid-cycle — the family arrived
5 days	$20	Late-cycle — just need a few more days of full speed

With 5 days left, $20 buys you unlimited high-speed data for those remaining days. That’s often worth it if you’re throttled to 0.5 Mbps and need to work or stream.

Standby ($8.50) → Roam Unlimited ($195)

Going straight from paused to full speed — common when you’re heading out for an extended trip and don’t want to think about data.

Days Remaining	Pro-Rata Charge	Scenario
25 days	$150	Early upgrade
15 days	$90	Mid-cycle
5 days	$30	Quick trip — full speed for the weekend

What About Residential Max (Half-Price Roam)?

If you’re on Starlink Residential Max ($139/month), your Roam plans are half price: 100GB costs $40/month and Unlimited costs $97.50/month. The pro-rata formula works exactly the same way — just with the discounted prices.

For example, upgrading from 100GB ($40) to Unlimited ($97.50) with 15 days left would cost about $15 instead of $60.

Our calculator handles Residential Max pricing — just toggle the Residential Max switch and it adjusts automatically.

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Tips to Save Money on Plan Changes

Understanding pro-rata billing opens up some smart strategies:

Time your upgrades. If you’re only a few days from your billing date, choose “Switch Later” instead of “Switch Now.” You’ll avoid the pro-rata charge entirely and just pay the full new plan price from your next cycle. If you’re 10+ days out and need the upgrade now, switching immediately makes more sense.

Use the “100GB first, then upgrade” strategy. Start each month on Roam 100GB ($80). If you burn through your data and need full speed back, upgrade to Unlimited for just the remaining days. The maths always works in your favour: even upgrading with 25 days left costs $180 total ($80 + $100 pro-rata) — still $15 less than paying $195 for Unlimited all month. Upgrade mid-cycle and you save $55. And the months you don’t need to upgrade at all? You save $115.

Downgrade before your billing date. Set a calendar reminder 1–2 days before your billing anniversary. Downgrades take effect at the next billing cycle, so you need to request the change before your billing date rolls over.

Use Standby between trips. At $8.50/month, Standby Mode is cheaper than cancelling and reactivating. You keep your account active, firmware stays updated, and you can upgrade to a Roam plan instantly when your next trip starts.

Monitor your data. The Starlink app shows your current cycle usage. Starlink sends alerts at 80GB and 100GB, but checking regularly means you can plan ahead rather than react. For detailed data-saving tips, see our guide: Where Did My 100GB Go? The Data Traps Nobody Warns You About.

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How to Find Your Billing Date

Your billing date is set when you first activate your Starlink account, and every plan change calculation is based on this date. To find yours:

On Desktop: Log into your Starlink account at starlink.com → click “Manage” → look for your billing information and next payment date.

On Mobile (Starlink App): Open the app → tap your account icon → look for subscription or billing details showing your next payment date.

Note: Starlink uses UTC time for billing. In Australia, that means your billing date rolls over at 10am AEST (11am AEDT), 9:30am ACST, or 8am AWST. If you’re making a change close to your billing date, timing can matter.

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Try Our Comprehensive Plan Change Calculator

We built a comprehensive Starlink Plan Change Calculator so you can see your exact pro-rata charge before you make any changes.

Here’s what it does:

• Set your billing anniversary date
• Select your current plan and your new plan
• Toggle Residential Max pricing if applicable
• Choose whether you’re switching now or at your next billing date
• See a full breakdown: daily rates, credits, costs, and your estimated charge

No signup required. No email capture. Just move the sliders and get your answer.

→ Try the Plan Change Calculator

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Current Australian Starlink Plan Prices

For reference, here are the current Australian Roam plan prices used in all calculations above:

Plan	Standard Price	Residential Max Price
Standby Mode	$8.50/month	$8.50/month
Roam 100GB	$80/month	$40/month
Roam Unlimited	$195/month	$97.50/month

Prices are in AUD and current at the time of writing. Starlink may change pricing at any time — we’ll update this guide when they do.

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Frequently Asked Questions