Cloud Backup Time Estimator

This estimator works out how many days a first cloud backup of your NAS takes over your internet upload, and how long the daily backups take after it. Use a speed you have measured for the most realistic answer; with only your nbn tier, it uses that tier's upload and says which planning assumption it applied.

On nbn your upload, not your download, sets the pace of a cloud backup, and home upload speeds are a fraction of the download. A first backup of a few terabytes can take weeks; the daily backups after it are usually much smaller.

Measured beats assumed. If you enter a measured upload, or better your backup software's own speed from a previous job, it is used exactly as entered. Without one, the estimate uses NTK's planning assumption of 75% of plan upload speed, an editorial figure, not a measurement.

Your data

Data to back up

Decimal units: 1 TB = 1,000 GB.

Logical data changed per day (% of the data)

The amount of data that changes each day, not the number of files touched. Used for the daily backups after the first upload.

Your upload

nbn tier and connection type

nbn's wholesale upload speed for your tier. Your provider's plan can differ.

Plan upload speed (Mbps)

Not used: your measured speed replaces the plan speed.

Measured upload speed (optional, Mbps)

From a speed test on a wired connection, ideally in the evening. Used as it is, instead of the plan.

Not used: your measured backup speed replaces it.

Measured backup speed (optional, MB/s)

Data backed up per second, before any compression or deduplication: the data a previous upload backed up divided by the time it took, as your backup software reports it. The best figure: it replaces both of the above.

Hours a day it can upload

First full backup

…

Speed used

Uploaded per day

Upload window

Daily backups after the first upload

Changed data a day

Upload time a day

What would help

Assumptions this result used

How we calculate

Speed used, best first: your measured backup speed (MB/s); else your measured upload (Mbps ÷ 8 = MB/s); else your plan upload × 75%, NTK's planning assumption. Measured figures are used as entered, with nothing taken off.
Active upload time = data ÷ speed used. Calendar days = active time ÷ the hours a day it can upload, so 8 hours a day takes three times as many days as 24. The first backup time is for your data as it stands when the upload starts: it does not include data that changes while the upload runs.
Line rate. With a plan speed, the result also shows the time at the full line rate, the fastest the line itself could carry the data.
Ranges. On FTTN, FTTB and Fixed Wireless, nbn gives an upload range rather than one figure, and the maximum can fall anywhere in it, so the result is a range too.
Daily backups = logical changed data per day ÷ the same speed. If even the fast end takes longer than the daily window, the backlog grows every day; if only the slow end of an upload range does, it may or may not, depending on where your line sits in that range.
Units. Decimal: 1 TB = 1,000 GB. Upload speeds in megabits per second (Mbps), backup software speeds in megabytes per second (MB/s); 8 bits make a byte.

Why 75% when you have not measured anything: backup software, encryption, the provider's servers and evening congestion can all keep a backup below the line speed. 75% is NTK's editorial planning figure for that, not a measured average. For the line itself: In the ACCC's latest report (measurements collected March 2026), NBN fixed line services averaged 90.4% of their plan upload speed during busy hours. This measures the line, not cloud backup software. (ACCC, checked 2026-10-07) In the ACCC's latest report, NBN fixed wireless services averaged 70.1% of plan upload speed across all hours and 63.7% in busy hours. (ACCC, checked 2026-10-07) The ACCC Measuring Broadband Australia program concluded at the end of June 2026; its final performance report was released on 17 June 2026. (ACCC, checked 2026-10-07)

Worked examples

From the plan speed. 4 TB over a 20 Mbps upload (nbn Home Standard on FTTP, FTTC or HFC), 24 hours a day: 24.7 days at the 75% planning assumption, 18.5 days at the full line rate.

From a measured upload. The same 4 TB with a measured 18 Mbps upload: 20.6 days, with no 75% applied. With your backup software's own measured 3 MB/s: 15.4 days.

Overnight only. Uploading 8 hours a day at the planning speed: 74.1 days, three times as long.

On FTTN or FTTB. Home Standard on FTTN gives an upload of 5 to 20 Mbps, so the same 4 TB takes 24.7 to 98.8 days at the planning assumption. A measured upload narrows that to one answer.

Daily backups. 0.5% of 4 TB is 20 GB a day, about 2 h 58 min over the 20 Mbps upload at the planning assumption.

nbn upload speeds and cloud backup time

The upload speed for each nbn home tier by connection type, and how long a first cloud backup takes over it uploading 24 hours a day. These are nbn's wholesale speeds, the most nbn sells to providers; your plan and line can be slower, and on ranges the maximum can fall anywhere in the range.

nbn tier	Connection type	Upload (Mbps)	1 TB at 75% planning	5 TB at 75% planning	5 TB at full line rate
Home Basic I	all fixed line	1	123.5 days	617.3 days	463 days
Home Basic II	FTTN, FTTB	5 to 10	12.3 to 24.7 days	61.7 to 123.5 days	46.3 to 92.6 days
Home Fast I	FTTN, FTTB	5 to 20	6.2 to 24.7 days	30.9 to 123.5 days	23.1 to 92.6 days
Home Standard	FTTN, FTTB	5 to 20	6.2 to 24.7 days	30.9 to 123.5 days	23.1 to 92.6 days
Home Basic II	FTTP, FTTC, HFC	10	12.3 days	61.7 days	46.3 days
Home Fast I	FTTC	20	6.2 days	30.9 days	23.1 days
Home Standard	FTTP, FTTC, HFC	20	6.2 days	30.9 days	23.1 days
Home Fast II	FTTP, HFC	50	2.5 days	12.3 days	9.3 days
Home Superfast	FTTP, HFC	50	2.5 days	12.3 days	9.3 days
Home Ultrafast	FTTP, HFC	100	1 day 5 h	6.2 days	4.6 days
Home Hyperfast	HFC	100	1 day 5 h	6.2 days	4.6 days
Home Hyperfast	FTTP	200	14 h 49 min	3.1 days	2.3 days
Fixed Wireless Basic I	Fixed Wireless	1	123.5 days	617.3 days	463 days
Fixed Wireless Basic II	Fixed Wireless	5	24.7 days	123.5 days	92.6 days
Fixed Wireless Home Fast	Fixed Wireless	8 to 20	6.2 to 15.4 days	30.9 to 77.2 days	23.1 to 57.9 days
Fixed Wireless Superfast	Fixed Wireless	10 to 40	3.1 to 12.3 days	15.4 to 61.7 days	11.6 to 46.3 days
Fixed Wireless Plus	Fixed Wireless	20	6.2 days	30.9 days	23.1 days

Upload speeds: nbn Co speed plans, checked 2026-10-07. Times: this estimator.

Why a faster download tier often does not help

Each nbn tier pairs a download speed with an upload speed, and several tiers share the same upload. nbn Home Fast II: 500 Mbps download and 50 Mbps upload. Available on FTTP and HFC only. (nbn co (nbnco.com.au), checked 2026-10-07) nbn Home Superfast: 750 Mbps download and 50 Mbps upload. Available on FTTP and HFC only. (nbn co (nbnco.com.au), checked 2026-10-07) Moving between those two changes the download only, so a cloud backup takes just as long. Compare the upload column, not the download. None of the home tiers on nbn's speed plans page has an upload as fast as its download. The highest upload listed is 200 Mbps, on Home Hyperfast over FTTP. Ask your provider which tiers your connection can get.

When the first upload is too long

Back up the data you could not replace first: documents and photos are often far smaller than a media library, so they are protected in days rather than months. Add the rest over time; once the first copy is up, only changes travel.

Some cloud providers can seed a backup from a physical device you send them, instead of the internet. Whether yours does, from Australia, and at what cost, varies by provider, so check before you plan around it.

If you use Backblaze B2: Backblaze calls this the Fireball. The Fireball is a Synology NAS with 96 TB of storage and a 10 gigabit Ethernet card, loaded on site and shipped back for upload into Backblaze B2. (Backblaze documentation, checked 2026-10-07) Backblaze charges a security deposit and a non-refundable shipping fee at order, for domestic orders only; international customers must contact Backblaze Support. Every Fireball ships from the US, even for accounts in a non-US data centre. (Backblaze documentation, checked 2026-10-07) A Fireball carries a rental fee for every 30 days, charged at the start of each period and not prorated, plus return shipping at the customer's cost. (Backblaze documentation, checked 2026-10-07) Seeding a Fireball for a third-party backup or archiving tool may need extra steps; often the data must be loaded with the partner's own tool. (Backblaze documentation, checked 2026-10-07) For an Australian account that means contacting Backblaze Support before relying on it.

A long upload also keeps the NAS running for weeks. To cost that electricity for your own NAS and tariff, use the NAS Power Cost Calculator.

Facts this page uses

Each fact below is taken from the publisher's own page and was re-found at the source on the date shown.

Fact	Applies to	Source
nbn speed tiers
nbn speeds are wholesale: the maximum nbn provides to internet providers. Where a tier is a range, the maximum can fall anywhere in it, and the lower figure is not a minimum speed.	nbn wholesale residential speed tiers (what nbn sells to providers, not retail speeds)	nbn co (nbnco.com.au), checked 2026-10-07
Broadband measurement (ACCC)
In the ACCC's latest report (measurements collected March 2026), NBN fixed line services averaged 90.4% of their plan upload speed during busy hours. This measures the line, not cloud backup software.	NBN fixed line services in the ACCC program, latest report (measurements collected March 2026), busy hours 7pm to 11pm weekdays	ACCC, checked 2026-10-07
In the ACCC's latest report, NBN fixed wireless services averaged 70.1% of plan upload speed across all hours and 63.7% in busy hours.	NBN fixed wireless services in the ACCC program, latest report	ACCC, checked 2026-10-07
The ACCC Measuring Broadband Australia program concluded at the end of June 2026; its final performance report was released on 17 June 2026.	ACCC Measuring Broadband Australia program	ACCC, checked 2026-10-07
Backblaze B2 Fireball
The Fireball is a Synology NAS with 96 TB of storage and a 10 gigabit Ethernet card, loaded on site and shipped back for upload into Backblaze B2.	Backblaze B2 Fireball program	Backblaze documentation, checked 2026-10-07
Backblaze charges a security deposit and a non-refundable shipping fee at order, for domestic orders only; international customers must contact Backblaze Support. Every Fireball ships from the US, even for accounts in a non-US data centre.	Backblaze B2 Fireball program	Backblaze documentation, checked 2026-10-07
A Fireball carries a rental fee for every 30 days, charged at the start of each period and not prorated, plus return shipping at the customer's cost.	Backblaze B2 Fireball program	Backblaze documentation, checked 2026-10-07
Seeding a Fireball for a third-party backup or archiving tool may need extra steps; often the data must be loaded with the partner's own tool.	Backblaze B2 Fireball program	Backblaze documentation, checked 2026-10-07

Frequently Asked Questions

Why does my cloud backup take so long?

Your upload speed sets the pace, and on nbn home plans the upload is a fraction of the download. 10 TB over a 20 Mbps upload takes about 46.3 days at the full line rate, or 61.7 days at NTK's planning assumption of 75% of plan upload speed, uploading 24 hours a day.

Does a faster download tier speed up cloud backup?

Only if it comes with a faster upload. nbn Home Fast II: 500 Mbps download and 50 Mbps upload. Available on FTTP and HFC only. nbn Home Superfast: 750 Mbps download and 50 Mbps upload. Available on FTTP and HFC only. Moving between those two tiers changes the download only, so it does not change backup time. Check the upload figure for your tier and connection type in the table on this page, not the download.

How can I speed up my first cloud backup?

Back up the most important data first (documents and photos are often far smaller than a media library) and add the rest over time. A plan with a higher upload speed helps if your connection type offers one. nbn Home Ultrafast: about 1000 Mbps download and 100 Mbps upload. Available on FTTP and HFC only. nbn Home Hyperfast: 2000 Mbps download; upload 200 Mbps on FTTP and 100 Mbps on HFC. Available on FTTP and HFC only. Some cloud providers can seed a backup from a physical device instead of the internet; check whether yours does. Backblaze offers this for its B2 service as the Fireball. The Fireball is a Synology NAS with 96 TB of storage and a 10 gigabit Ethernet card, loaded on site and shipped back for upload into Backblaze B2. Backblaze charges a security deposit and a non-refundable shipping fee at order, for domestic orders only; international customers must contact Backblaze Support. Every Fireball ships from the US, even for accounts in a non-US data centre. A Fireball carries a rental fee for every 30 days, charged at the start of each period and not prorated, plus return shipping at the customer's cost.

Does a backup really run at my full plan speed?

Not always, which is why the estimator uses NTK's planning assumption of 75% of plan upload speed when you have not measured anything. It is an editorial planning figure, not a measurement. In the ACCC's latest report (measurements collected March 2026), NBN fixed line services averaged 90.4% of their plan upload speed during busy hours. This measures the line, not cloud backup software. In the ACCC's latest report, NBN fixed wireless services averaged 70.1% of plan upload speed across all hours and 63.7% in busy hours. The ACCC Measuring Broadband Australia program concluded at the end of June 2026; its final performance report was released on 17 June 2026. Those figures describe the line, not backup software: encryption, the software and the provider's servers can be slower. If you measure your upload, or better your backup software's actual speed, enter it: a measured figure is used as it is, with no 75% applied.

Should I upload overnight only?

An 8-hour nightly window takes three times as many days as uploading 24 hours a day, because 8 hours is a third of a day; 12 hours a day takes twice as many. If you need the upload during the day, most backup software can limit its bandwidth at set times instead.

How long will daily backups take after the first upload?

Each daily run sends the data that changed: the logical changed data, not the number of files touched. At 0.5% of 4 TB a day that is 20 GB, about 2 h 58 min on a 20 Mbps upload at the planning assumption. If a day's changes take longer than your daily upload window, the backlog grows every day.

What units does this estimator use?

Decimal units: 1 TB = 1,000 GB and 1 GB = 1,000 MB. Upload speeds are in megabits per second (Mbps) and backup software speeds in megabytes per second (MB/s). 8 bits make a byte, so a 20 Mbps upload moves 2.5 MB/s at its full line rate.

Method last reviewed: 2026-10-14. Facts last checked at source: 2026-10-07.