How Many Zeros in a Quadrillion?

A quadrillion is written as:
1,000,000,000,000,000

That's: A 1 followed by fifteen zeros or 16 digits total (including the 1)

So the answer is: There are 15 zeros in a quadrillion.

What Is a Quadrillion?

A quadrillion is a massive number that few people use in day-to-day life, but it's incredibly important in science, data, and economics. It's defined as:

1,000 trillions
1,000,000 billions
1,000,000,000 millions
1,000,000,000,000,000 in standard form
10¹⁵ in scientific notation

Each new level in large numbers adds 3 more zeros, so a quadrillion is:
1,000 × trillion
Or 1,000,000 × billion

Zeros Comparison Table

Number Name	Numeric Form	Number of Zeros
Thousand	1,000	3
Million	1,000,000	6
Billion	1,000,000,000	9
Trillion	1,000,000,000,000	12
Quadrillion	1,000,000,000,000,000	15
Quintillion	1,000,000,000,000,000,000	18
Sextillion	1,000,000,000,000,000,000,000	21
Septillion	1,000,000,000,000,000,000,000,000	24

Real-World Examples of a Quadrillion

The word quadrillion isn't thrown around every day — but it pops up in powerful, fascinating contexts:

Time
1 quadrillion seconds = ~31.7 million years That's long before dinosaurs roamed Earth.
Money
Global derivatives market value is sometimes estimated in the quadrillions of dollars — mind-boggling.
Data
Petabyte-scale data centers (used by big tech companies) handle quadrillions of bytes regularly.
1 petabyte = ~1 quadrillion bytes (technically, 1,125,899,906,842,624 bytes or 2⁵⁰)
Science
There are estimated to be over 1 quadrillion ants on Earth at any time.

Memory Tricks to Remember 15 Zeros

Here's how to easily recall the number of zeros in a quadrillion:

1. Count the Jumps

Thousand (3 zeros)
Million (6 zeros)
Billion (9 zeros)
Trillion (12 zeros)
Quadrillion (15 zeros)
Add 3 zeros per level

2. Visual Grouping

1,000,000,000,000,000
→ (1)(000)(000)(000)(000)(000) → Five groups of 3 zeros

Quadrillion Comparison Table

Scale	Name	Zeros	Relative Size
10⁶	Million	6	Base level
10⁹	Billion	9	1,000 millions
10¹²	Trillion	12	1,000 billions
10¹⁵	Quadrillion	15	1,000 trillions
10¹⁸	Quintillion	18	1,000 quadrillions
10²¹	Sextillion	21	1,000 quintillions
10²⁴	Septillion	24	1,000 sextillions

Questions & Answers

How many digits does a quadrillion have?

A quadrillion has 16 digits in total — that’s the digit 1 followed by 15 zeros.

Is a 15-digit number a quadrillion?

Not exactly. A 15-digit number is just under a quadrillion. A true quadrillion is 1 followed by 15 zeros, which means it’s a 16-digit number.

What Comes Before Quadrillion?

The number that comes before a quadrillion is a trillion.

Trillion = 1,000,000,000,000 (that’s 12 zeros)
It’s written as 10¹² in scientific notation

A quadrillion is a thousand trillions.

What Comes After Quadrillion?

The next number after a quadrillion is a quintillion.

Quintillion = 1,000,000,000,000,000,000 (that’s 18 zeros)
It’s written as 10¹⁸

A quintillion is a thousand quadrillions.

Quick Comparison Chart

Name	Number of Zeros	Scientific Notation
Trillion	12	10¹²
Quadrillion	15	10¹⁵
Quintillion	18	10¹⁸

How many zeros in 2 quadrillion?

2 quadrillion = 2,000,000,000,000,000
That’s a 2 followed by 15 zeros.

How many zeros in 10 quadrillion?

10 quadrillion = 10,000,000,000,000,000
That’s a 1 followed by 16 zeros.

How many zeros in 100 quadrillion?

100 quadrillion = 100,000,000,000,000,000
That’s a 1 followed by 17 zeros.

How many zeros in half a quadrillion?

0.5 quadrillion = 500,000,000,000,000
That’s a 5 followed by 14 zeros.

How many zeros in a quadrillion in the British system?

In the long scale (historic British use), quadrillion = 10^24 (1 followed by 24 zeros). Today, the UK uses the short scale: 1 followed by 15 zeros.

Visualizing a Quadrillion

Need help imagining a number this big? Try these comparisons:

Pennies:
Laying 1 quadrillion pennies flat would cover the entire Earth's surface — twice.
Grains of sand:
Some scientists estimate that there are about 7.5 × 10¹⁸ grains of sand on Earth's beaches — a bit more than a quadrillion!
Stars in the Universe:
The estimated number of stars in the observable universe is roughly 1 quadrillion times 100 million — even quadrillions start to feel small in that context.

Quadrillion

A quadrillion has 15 zeros
It equals 1,000,000,000,000,000
In scientific form: 10¹⁵
It's 1,000 times bigger than a trillion

A quadrillion is a number so large it's hard to truly grasp — but understanding how many zeros it has, and where it fits in the scale of large numbers, gives you a sharper sense of scale, science, and reality. From data to dollars to ants on Earth, quadrillions are all around us — quietly measuring the massive.