Microvolts to Volts (µV to V) - Precision Measurement

Reading Microvolts When the Spec Is Written in Volts

Converting microvolts to volts is a six-decade jump, and it is the jump you make every time a bench meter shows an offset in µV while the tolerance, the certificate or the test-point label is written in V. This page keeps both numbers on screen at once so nothing gets lost in a count of zeros.

Conversion factor: 1 µV = 0.000001 V (1 × 10⁻⁶ V) — divide microvolts by 1,000,000. Worked example: a shorted-input meter settles at 47 µV, so 47 ÷ 1,000,000 = 0.000047 V, which against a 1 V test point is 47 parts per million of reading.

Why This Scale Turns Up Every Day

A million counts, one range

1 V contains 1,000,000 µV — exactly the span a 6½-digit bench meter resolves on its 1 V range. The reading is in volts, the last digit is a microvolt.

Error budgets are written in µV

Thermal EMFs, amplifier offsets and drift are quoted in microvolts; the quantity they corrupt is quoted in volts. Comparing the two means moving one of them six decades.

Below 1 µV the display changes form

Results under 1 × 10⁻⁶ V are shown in scientific notation instead of a long decimal, so nanovolt-level figures survive the round trip intact.

The volt is realized down here

National labs reproduce the volt from the Josephson effect to roughly one part in 10¹⁰ — about 1 nV at 10 V, three decades below a single microvolt.

Converting a Bench Reading Into Volts

The workflow below matches how the number usually travels: off the meter, through the converter, into a worksheet or report.

Type the reading as the meter shows it

Enter the microvolt figure in the left field (it starts at 1). Comma and dot both work as the decimal separator and spaces are ignored, so a pasted log value reads cleanly.

Point it the way your paperwork runs

Both fields are live: type a volt figure on the right and the µV equivalent appears on the left — useful when a spec says 0.00005 V and you need the margin in microvolts. The swap button (↔) reverses the pair outright.

Read the volt value

Output is rounded to at most eight decimals, thousands grouped by a space. Anything below 1 × 10⁻⁶ V switches to scientific notation — 0.5 µV prints as 5.000000e-7.

Copy the bare number into the record

The copy button on each field puts only the digits on the clipboard — no unit, no spaces — so it drops straight into a worksheet cell. Ctrl+C inside a field does the same.

Runs in the browser: every conversion is computed on your own machine once the page has loaded — no reading is sent anywhere.

What a Microvolt Figure Means on Precision Instruments

A microvolt is abstract until you put it next to the hardware that produces it. The figures below are the ones a calibration or precision-measurement person meets in practice, each shown with its volt equivalent.

Where it shows up	Typical figure	Same value in volts
6½-digit DMM, 1 V range — value of the last displayed digit	1 µV	0.000001 V
6½-digit DMM, 100 mV range — last digit	0.1 µV	0.0000001 V
Thermal EMF, copper to tin/lead solder — per °C of gradient	≈5 µV/°C	0.000005 V per °C
Thermal EMF, clean copper to copper — per °C of gradient	<0.2 µV/°C	<0.0000002 V per °C
Zero-drift precision op-amp — input offset voltage	0.25–5 µV	0.00000025–0.000005 V
Same amplifier — offset drift with temperature	0.005 µV/°C	0.000000005 V per °C
Johnson–Nyquist noise, 1 kΩ in 1 Hz — at room temperature	≈0.004 µV (4 nV)	0.000000004 V
Josephson voltage standard at 10 V — combined uncertainty	≈0.0015 µV (1.5 nV)	0.0000000015 V

Read down the column and the point of the conversion is obvious: one soldered lug in a 2 °C gradient contributes roughly 10 µV — 0.00001 V, ten counts of the last digit on a 6½-digit meter — while the reference it measures may be certified to a thousandth of that.

What This Converter Does for That Work

Enter From Whichever End You Have

Reading in µV, tolerance in V — type into either field and the other tracks live, keeping measured and specified values side by side.

Exponent Form Below 1 µV

Sub-microvolt results appear as e.g. 4.000000e-9 V — eight decimal places would round a 4 nV figure to zero.

Clipboard-Clean for Reports

Copy returns the number alone, without unit or grouping spaces, so an uncertainty budget takes it without re-typing.

Nanovolts and Picovolts on Hand

A searchable menu on both sides covers all twelve units — nanovolt and picovolt included, alongside the CGS abvolt and statvolt.

Precision Measurement Questions

What does 6½ digits actually mean in microvolts?

Six full digits plus a leading half digit that only reaches 1 — a count running to about 1,199,999. On the 1 V range full scale is roughly 1.2 V, so the last digit is worth 1 µV = 0.000001 V; on the 100 mV range the same structure gives 0.1 µV per digit. That is why the range is labelled in volts while the resolution is quoted in microvolts.

Why is my result displayed as 5.000000e-7 instead of a decimal?

The output switches to exponent form whenever the value falls below 1 × 10⁻⁶ V (or climbs to 1 × 10¹⁰). Exactly 1 µV is 0.000001 V and still prints as a decimal; 0.5 µV becomes 5.000000e-7. The reason is practical: decimals are capped at eight places, so a 4 nV figure would round to 0.00000000, and long runs of zeros are easy to miscount when transcribing.

Where does thermal EMF come from and how many microvolts does it add?

Any junction of two dissimilar metals in a temperature gradient generates a Seebeck voltage. Relative to copper, published coefficients run from under 0.2 µV/°C for clean copper-to-copper and 0.3 µV/°C for gold or silver, to about 5 µV/°C for tin/lead solder, 10 µV/°C for nickel-plated banana plugs and over 1000 µV/°C for oxidised copper. Two degrees across an ordinary soldered joint is therefore around 10 µV — 0.00001 V — often the largest single error term in a low-level DC measurement.

Can a handheld multimeter resolve microvolts?

Rarely in any useful sense. A common 3½-digit handheld steps in 0.1 mV — 100 µV, or 0.0001 V — on its lowest DC range, and a good 4½-digit model reaches roughly 10 µV. Even then resolution is not accuracy: its own specification, plus thermal EMFs in the leads and jacks, sits at or above those last digits. Genuine microvolt work uses a 6½-digit or better bench DMM, or a nanovoltmeter.

What does a null or REL measurement do for microvolt-level work?

REL (relative, or null) stores the present reading as a reference and shows only the difference from it. Short the input with a low-thermal-mass short, let it settle, press REL, and the meter's residual offset plus the thermal EMF of that connection drops out of every reading after — the microvolt-scale terms no calibration certificate can remove for you. Its limit: it cancels only what was there when you pressed it, so later drift returns. Reversing lead polarity and averaging is the usual companion technique.

Microvolts to Volts