Unit Converter – Complete Guide to Technical Units and Unix Timestamps

You are reading a log that says a backup moved 4.7 GB, a monitoring graph in Mbit/s, a vendor datasheet in MiB/s, and an API response with "created": 1700000000. Every one of those needs a conversion before you can compare it with anything else, and every one has a trap: decimal versus binary prefixes, bits versus bytes, seconds versus milliseconds.

The Unit Converter handles the technical units admins meet daily — data storage, transfer rates, frequency, time, voltage, current, power and temperature — plus Unix timestamps in both directions. It runs entirely in your browser and converts with exact fractions, so 0.1 GB really becomes 100 MB, not 99.99999999999999.

What is the Unit Converter?

In simple terms

You enter a value, pick the unit it is in and the unit you want, and the tool shows the result plus the same value in every other unit of that type. A separate tab turns Unix timestamps into readable dates and dates back into timestamps.

Technical background

Each unit has a conversion factor to a base unit of its quantity: bit for data, bit/s for rates, hertz for frequency, second for time, volt, ampere and watt. Converting from unit A to unit B is value × factorA ÷ factorB.

Two prefix families exist for data:

• Decimal (SI) prefixes multiply by 1000 per step: kB, MB, GB, TB, PB. These are what drive vendors and network equipment use.
• Binary (IEC) prefixes multiply by 1024 per step: KiB, MiB, GiB, TiB, PiB. The IEC introduced them so "kilo" would not mean two different numbers.

Temperature cannot use a single factor because the scales have different zero points. The converter goes through kelvin: K = °C + 273.15 and °F = °C × 9/5 + 32.

Unix time counts seconds since 1970-01-01 00:00:00 UTC and does not count leap seconds. Negative values are dates before 1970.

Why use the Unit Converter?

• Bits versus bytes. Comparing an ISP's Mbit/s with a browser's MB/s is a factor-of-8 problem that is easy to get wrong in your head.
• GB versus GiB. Capacity planning, VM sizing and quota discussions go wrong when one side means 10⁹ bytes and the other 2³⁰.
• No rounding drift. Most calculators use floating-point numbers, so repeated decimal conversions pick up tiny errors. This one keeps values as exact fractions and only rounds what it displays.
• Timestamps in logs and APIs. Turning 1700000000 into 2023-11-14T22:13:20.000Z (and checking whether a 13-digit value is milliseconds) is a constant chore when reading logs, JWT claims or database rows.
• Electrical sanity checks. Quick mW/W/kW or mA/A conversions when reading PSU, PoE or UPS specifications.

Who should use it?

System administrators and DevOps engineers reading logs and metrics, network engineers comparing link speeds with transfer rates, developers debugging timestamps in APIs, and anyone sizing storage or reading hardware datasheets. If you only work with storage sizes, the focused Data Storage Converter shows decimal and binary results side by side; for clock speeds there is the CPU Frequency Converter.

How the Unit Converter works

Everything happens in your browser; nothing you type is sent to a server.

1. Parsing. Your input is read as an exact decimal. Spaces, underscores, apostrophes and thin spaces are ignored. A single comma is a decimal separator (1,5 = 1.5); when a dot is also present or there are several commas, commas are thousands separators (1,234.5). Exponents such as 1.5e3 are accepted, up to an exponent of ±400, and inputs are limited to 200 characters.
2. Exact arithmetic. The value becomes a fraction of two arbitrary-size integers (BigInt). Unit factors are exact fractions too, so 1 TB → GiB is computed as 10¹² ÷ 1024³ with no intermediate rounding.
3. Display. Results are rounded half away from zero to at most 10 decimal places, with trailing zeros removed and the integer part grouped with spaces. If the true value has more digits, the result line says "rounded to 10 decimal places". Values with more than 30 integer digits switch to scientific notation, and tiny non-zero values that would round to 0 are shown in scientific notation as well.
4. Validation. Data, rate and frequency values cannot be negative. Temperatures below 0 K are rejected with an error explaining the limit (0 K = −273.15 °C = −459.67 °F).

The units available per type are:

Note that the data type has a single bit unit (no kbit or Mbit for sizes); bit-based multiples exist only for transfer rates. "KB" with a capital K is accepted as an alias of the decimal kilobyte, kB.

Unix timestamps use the browser's Date object. In auto-detect mode, a number with 12 or more integer digits is read as milliseconds, anything shorter as seconds; the tool always says which interpretation it chose. Dates must be within the JavaScript date range (about ±275,000 years around 1970). For date input it accepts YYYY-MM-DD, YYYY-MM-DDTHH:mm[:ss[.sss]] (a space instead of T works too), optionally followed by Z or an offset such as +03:00. Impossible dates such as 2026-02-30 are rejected rather than silently rolled over.

How to use the NetTools.tech Unit Converter

1. Open the Unit Converter.
2. Choose a conversion type: Data storage, Transfer rate, Frequency, Time, Voltage, Current, Power, Temperature or Unix timestamp. You can deep-link a type with a hash, for example /unit-converter#rate or /unit-converter#timestamp.
3. Optional: type a unit into Find a … unit (for example MiB or mbps). The search only looks in the selected type and sets the match as the From unit.
4. Enter the Value, pick From and To. Results update as you type.
5. Use the swap button to exchange the units; the current result becomes the new value, so a round trip shows your original number. Reset restores the defaults.
6. For timestamps: the panel shows the current Unix time in seconds and milliseconds with copy buttons. Enter a timestamp in Timestamp → date and choose Auto-detect, Seconds or Milliseconds. In Date → timestamp, enter a date and choose whether it is Local time or UTC. Use now below fills both fields with the current time.
7. Export with CSV, JSON, Copy all or Print. Exports include the inputs, result, a "Value in every unit" table and the assumptions (prefix system, rounding).

Understanding the results

Example: link speed, storage and a log timestamp

A backup job report says it transferred 4.7 GB over a link that monitoring shows as 100 Mbit/s, and the log line carries 1700000000.

• Data storage, 4.7 GB → GiB: 4.3772161007 GiB (rounded to 10 decimal places). The operating system will show roughly 4.38 "GB".
• Transfer rate, 100 Mbit/s → MB/s: 12.5 MB/s. In binary units the same rate is 11.9209289551 MiB/s (rounded).
• Unix timestamp 1700000000, Auto-detect: "Interpreted as seconds." UTC (ISO 8601) is 2023-11-14T22:13:20.000Z and the HTTP date is Tue, 14 Nov 2023 22:13:20 GMT. Entering 1700000000000 instead gives the same instant with the note "Interpreted as milliseconds (13 digits)".
• Temperature, −40 °C → °F: −40, the one point where both scales agree; 20 °C → K is 293.15.

For the transfer time itself, the Bandwidth Calculator does the division for you: 4.7 GB at 100 Mbit/s takes 6 min 16 s in theory.

Common use cases

• Converting ISP and switch-port speeds (Mbit/s, Gbit/s) to the MB/s shown by browsers, rsync or scp.
• Translating storage quotas and VM disk sizes between GB and GiB before filing a ticket.
• Reading epoch values from logs, JSON Web Token exp/iat claims, database columns or date +%s output.
• Producing an epoch value for a given date, for example for a query filter or a cron-driven script.
• Checking PoE budgets and UPS loads in W and kW, or sensor readings in mA.
• Converting latency budgets between ms, µs and ns.

Troubleshooting

"That is below absolute zero"

The temperature you entered is colder than 0 K. Check the selected From unit: −300 is a valid Fahrenheit value only above −459.67 °F, and never valid in Celsius below −273.15.

"Data storage cannot be negative"

Data sizes, rates and frequencies must be zero or positive. Remove the minus sign, or use a type that allows negatives (time, voltage, current, power, temperature).

The result is a thousand times too small

You probably typed a comma as a thousands separator with no dot, for example 1,234. A single comma is read as a decimal comma, giving 1.234. Type 1234, 1 234 or 1,234.0.

The timestamp lands in 1970 or in the far future

A millisecond value was read as seconds, or the other way round. Look at the note under the input and switch the unit select from Auto-detect to Seconds or Milliseconds. Values with 12 or more integer digits are treated as milliseconds automatically.

The local time is not what a colleague sees

Local times use your browser's time zone. Compare the UTC (ISO 8601) line instead, or enter the date with Z or an explicit offset so it is unambiguous.

Common mistakes

• Treating MB and MiB as the same unit. The gap is 4.86% at mega, 7.37% at giga and almost 10% at tera.
• Forgetting the factor 8. Mb is megabit, MB is megabyte.
• Using days and weeks for calendar math. The converter's day is exactly 86,400 s; across a daylight-saving change a calendar day can be 23 or 25 hours.
• Copying a local time into a ticket without the offset. Use the ISO 8601 line with offset or the UTC value.
• Assuming the search box searches everything. It only searches the selected conversion type; switch types first.

Limitations

• Conversions are mathematical. The tool does not know what a vendor or operating system means by an ambiguous "GB" label; you choose the unit.
• Displayed results are rounded to 10 decimal places (exports use the same plain values). Use the exact equation when you need more precision.
• Unix time ignores leap seconds, and dates are limited to the JavaScript date range.
• Local-time output depends on your browser and device time zone database.
• Rates only include byte units up to GB/s and GiB/s; sizes up to PB and PiB. There are no non-metric units such as miles or pounds.

Security & privacy

All conversions run locally in your browser; your values, dates and results are not sent anywhere. Like every NetTools.tech tool page, the page may send an anonymous usage counter (which tool, and whether it was viewed or used) unless your browser sends Global Privacy Control or Do Not Track — no inputs or results are included. There is nothing sensitive to enter here, but avoid pasting whole log lines or tokens just to read a timestamp; copy only the number.

Related tools

• Data Storage Converter — sizes only, with a decimal-versus-binary comparison. Guide: Data Storage Converter guide.
• CPU Frequency Converter — Hz to THz plus the clock period. Guide: CPU Frequency Converter guide.
• Bits & Bytes Explainer — the background behind bits, bytes and prefixes. Guide: Bits and bytes guide.
• Bandwidth Calculator — transfer time, data volume and required bandwidth. Guide: Bandwidth Calculator guide.
• Number Base Converter — binary, octal, decimal, hex and other bases.
• Overview of the whole category: Conversion & calculation tools.

Summary

The Unit Converter covers data, rates, frequency, time, electrical units, temperature and Unix timestamps, and converts with exact fractions so decimal and binary prefixes never drift. It only rounds what it displays and tells you when it did. Watch the comma rule, pick the right prefix family, and use the UTC line when sharing timestamps.

Frequently asked questions

What is the difference between MB and MiB?

MB (megabyte) is a decimal unit of 1,000,000 bytes, while MiB (mebibyte) is a binary unit of 1,048,576 bytes (1024²). The converter lists decimal and binary units in separate groups, so 1 MiB converts to exactly 1.048576 MB.

Why does my 100 Mbit/s connection download at about 12 MB/s?

Network speeds are quoted in bits per second and download managers show bytes per second. 100 Mbit/s divided by 8 is 12.5 MB/s, the theoretical maximum, and protocol overhead takes a little more off in practice.

Is a Unix timestamp in seconds or milliseconds?

Classic Unix time is in seconds, which is 10 digits for current dates; JavaScript and many APIs use milliseconds, which is 13 digits. The converter treats numbers with 12 or more integer digits as milliseconds when auto-detect is selected, tells you which interpretation it used, and lets you force seconds or milliseconds.

Which time zone does the Unix timestamp conversion use?

A Unix timestamp itself is always UTC. The converter shows the UTC time and your browser's local time with the time zone name and offset, and when you convert a date back to a timestamp you choose whether the date is read as local time or UTC.

Why does the converter accept 1,5 as 1.5?

A single comma without a dot is treated as a decimal separator, so 1,5 becomes 1.5. Commas are only treated as thousands separators when a dot is also present or when there is more than one comma, so type 1234 or 1,234.0 if you mean one thousand two hundred thirty-four.

Can I convert negative values?

Time, voltage, current, power and temperature accept negative values, because they have a physical meaning there. Data sizes, transfer rates and frequencies cannot be negative and are rejected, and temperatures below absolute zero produce an error.

Are days and weeks exact in the time conversion?

Yes. A day is exactly 86,400 seconds and a week 604,800 seconds in this converter. Leap seconds and daylight-saving shifts are deliberately ignored, which is what you want for durations but not for calendar arithmetic.