Home › Unit Converters › Font Size Converter
Font Size Converter
Convert font sizes between pixels, points, em, rem, percent and vw. Set your root font size, parent size and viewport to match your design, then copy the CSS.
Last updated:
Context
px
Browser default is 16px.
px
px
e.g. 390 phone, 768 tablet, 1440 laptop
Enter your values to see the result.
Advertisement
Advertisement
How to use the Font Size Converter
- Enter the font size you have, e.g. 24.
- Choose the From and To units, e.g. px to rem.
- Check the context: root size for rem (16px by default), parent size for em and %, and the viewport width for vw.
- Read the result and all other units in the results panel, and see the live preview.
- Copy the CSS with Copy results, or download the 6–72px chart as CSV.
Font size units explained
All conversions go through CSS pixels, using these formulas (root and parent sizes in px):
- px: the CSS reference pixel, 1/96 of an inch. Absolute.
- pt: a typographic point, 1/72 inch.
px = pt × 96 ÷ 72(1pt = 1.3333px). Used in print and word processors. - rem: relative to the root html font size.
px = rem × root. - em: relative to the parent element's font size.
px = em × parent; nested em values multiply. - %: for font-size, a percentage of the parent's font size.
px = % ÷ 100 × parent, so 100% = 1em. - vw: 1% of the viewport width.
px = vw ÷ 100 × viewport width.
Common font sizes (16px root)
| Pixels | Points | Rem / em | Percent | Typical use |
|---|---|---|---|---|
| 10px | 7.5pt | 0.625rem | 62.5% | fine print, legal notes |
| 12px | 9pt | 0.75rem | 75% | captions, labels |
| 14px | 10.5pt | 0.875rem | 87.5% | small UI text, table cells |
| 16px | 12pt | 1rem | 100% | body text (browser default) |
| 18px | 13.5pt | 1.125rem | 112.5% | comfortable reading text |
| 20px | 15pt | 1.25rem | 125% | lead paragraph, h5 |
| 24px | 18pt | 1.5rem | 150% | h3 / h2 on mobile |
| 32px | 24pt | 2rem | 200% | h1 on mobile, h2 on desktop |
| 48px | 36pt | 3rem | 300% | large desktop headline |
| 64px | 48pt | 4rem | 400% | hero / display text |
Practical tips
- Use rem for text so your type respects the visitor's browser font setting, and px only for things that should not scale, such as hairline borders.
- Fluid headings: combine units with
clamp(), e.g.font-size: clamp(1.75rem, 1rem + 2.5vw, 3rem), to grow with the screen but stay within limits. - Print and PDF: designers often specify pt. Convert to px with ×4/3 before building the web version, so 10.5pt becomes 14px.
- Watch nested em: a 1.2em list inside a 1.2em container ends up at 1.44 × the parent size. Switch to rem when sizes compound unexpectedly.
Frequently asked questions
How do I convert px to pt?
Multiply pixels by 0.75. CSS defines 1px as 1/96 inch and 1pt as 1/72 inch, so 16px = 12pt and 24px = 18pt. To go from pt to px, multiply by 4/3 (1.3333).
How many pixels is 1rem?
1rem equals the root (html element) font size, which is 16px in all major browsers unless the user or your CSS changes it. So 1.5rem = 24px with the default root size.
What is the difference between em and rem?
rem is always relative to the root html font size, while em is relative to the font size of the parent element (or the element itself for properties other than font-size). Nested em values multiply, which is why rem is easier to predict.
Is 12pt the same as 16px?
Yes. 12pt × 96 ÷ 72 = 16px. That is why 12pt in a word processor and the 16px browser default look about the same size.
How is vw calculated for font sizes?
1vw is 1% of the viewport width. On a 1440px-wide screen 1vw = 14.4px, so a 48px heading is 3.3333vw. Pure vw text does not respect user zoom settings well, so many designers combine it with rem in clamp().
What is the 62.5% font size trick?
Setting html { font-size: 62.5% } makes the root 10px (62.5% of 16px), so 1.6rem = 16px and 2.4rem = 24px. Set the root to 10 in this converter to work with that setup.
Should I use px or rem for font sizes?
rem is generally recommended for text, because it scales when visitors change their browser's default font size. px values stay fixed, which can hurt accessibility for people who need larger text.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.
Related tools
PX to REM ConverterConvert px to rem or em and back, with a 1-100px table and a whole-CSS converter.PX to PTConvert pixels to points (px to pt) instantly, with formula and chart.PX to EM ConverterConvert pixels to em using the parent font size, and em back to px, with conversion tables.PX to VW ConverterConvert pixels to vw and vh for any viewport size, and vw/vh back to px, with breakpoint tables.Currency ConverterConvert currencies with live exchange rates.Unit ConverterConvert length, weight, volume, temperature and more.Roman Numeral ConverterConvert numbers to Roman numerals and back, up to 3,999,999.Number to WordsWrite any number in words, including cheque format.Words to NumberConvert written English number words back into digits.Ordinal Number GeneratorTurn numbers or ranges into ordinals like 1st, 2nd, 3rd or first.Time Zone Abbreviations & UTC OffsetsLook up time zone abbreviations like EST, CET or IST and their UTC offsets.Shoe Size ConverterConvert US, UK, EU and JP shoe sizes for men, women and kids, or size from foot length.Clothing Size ConverterConvert women's, men's and kids' clothing sizes between US, UK, EU, IT, FR, JP and AU.Ring Size ConverterConvert US, UK, EU and JP ring sizes, find a size from diameter, and print a ring sizer.Bra Size CalculatorFind your bra size from two measurements and convert it between US, UK, EU, FR and AU sizes.Paper Size ReferenceA, B, C, US and ANSI paper sizes in mm, inches, points and pixels at any DPI, with a visual compare.Fraction to Decimal CalculatorConvert fractions and mixed numbers to exact decimals with repeating digits and percent.Decimal to Fraction CalculatorTurn decimals and repeating decimals into simplified fractions and mixed numbers.km/L to MPGConvert kilometers per liter to miles per gallon and back, with formula steps.Paper Weight ConverterConvert gsm to lb bond, text, cover and index paper weights, with a thickness guide.UK MPG to US MPGConvert UK miles per gallon to US miles per gallon and back, with formula steps.Fraction to PercentConvert a fraction or mixed number to a percentage and decimal, with repeating digits and steps.Percent to FractionConvert any percentage, including decimals like 12.5%, to a simplified fraction and mixed number.Repeating Decimal to FractionConvert a repeating decimal like 0.1(6) into an exact simplified fraction, with algebra steps.Asian Size Chart ConverterConvert Asian and China clothing sizes (S–5XL, 160/84A) to US, UK and EU sizes from your chest.Baby Clothing Size ConverterConvert baby sizes (preemie, NB, 0–3M to 24M) to weight, length, EU cm and UK sizes.Beaufort Scale ConverterConvert wind speed in mph, km/h, knots or m/s to Beaufort force with sea and land signs.Blood Sugar ConverterConvert blood glucose between mg/dL and mmol/L and see where the reading falls.Bra Sister Size CalculatorFind bra sister sizes (band up, cup down and band down, cup up) with a full sister-size grid.Bra Size ConverterConvert bra sizes between US, UK, EU, French, Australian and Japanese sizing.CAD to USDConvert Canadian dollars to US dollars at the daily ECB reference rate, with a 30-day chart.Coordinate ConverterConvert GPS coordinates between decimal degrees, DMS, DDM, UTM and MGRS, auto-detected.Crochet Hook Size ConverterConvert crochet hooks between mm, US letters and UK sizes, incl. steel hooks and yarn pairing.Decimal to Percent ConverterTurn decimals into percentages with the rounding you choose; convert a list at once.Drill Bit Size ConverterConvert drill bits between fractional, number, letter and metric sizes with decimal inches.EU to US Shoe SizeConvert EU shoe sizes to US men's, women's and kids' sizes, plus UK and foot length.EUR to USDConvert euros to US dollars at the daily ECB reference rate, with a 30-day chart.Fuel Economy ConverterConvert US MPG, UK MPG, L/100km, km/L and mi/L, and compare two vehicles' fuel costs.Scale ConverterConvert real sizes to model or drawing scale and back: 1:87 HO, 1:24, 1/4" = 1' and more.Sheet Metal Gauge ConverterSheet metal gauge to inches and mm for steel, galvanized, stainless and aluminum, and back.USD to CADConvert US dollars to Canadian dollars at the daily ECB reference rate, with a 30-day chart.USD to EURConvert US dollars to euros at the daily ECB reference rate, with a 30-day chart.USD to GBPConvert US dollars to British pounds at the daily ECB reference rate, with a 30-day chart.USD to INRConvert US dollars to Indian rupees with daily ECB rates, lakh/crore and a 30-day chart.USD to JPYConvert US dollars to Japanese yen with daily ECB rates, amount tables and a 30-day chart.USD to MXNConvert US dollars to Mexican pesos at the daily ECB reference rate, with a 30-day chart.SAE to Metric Wrench ConverterConvert SAE wrench and socket sizes to metric mm and back, with interchangeable sizes flagged.Climbing Grade ConverterConvert climbing grades between YDS, French, UIAA and Ewbank, and bouldering V-scale to Font.Satoshi to Bitcoin ConverterConvert sats to BTC, mBTC, bits and msat and back, with optional USD at your own price.Add Commas to NumbersFormat numbers with thousands separators (comma, space or period), or remove them, in bulk.Capacitance ConverterConvert F, mF, µF, nF and pF, and encode or decode 3-digit capacitor codes like 104.Lat Long to UTMConvert latitude/longitude (decimal or DMS) to UTM zone, easting and northing, one or in bulk.UTM to Lat LongConvert UTM zone, easting and northing (WGS84) to latitude/longitude in decimal and DMS, or a CSV batch.Engineering Notation ConverterConvert numbers to engineering notation with SI prefix, scientific notation and standard form.Excel Column Letter to NumberConvert spreadsheet column letters (A, AA, XFD) to numbers and back, one or many at once.Improper Fraction to Mixed NumberTurn improper fractions into simplified mixed numbers with long division and a bar model.Men's Suit Size ConverterConvert men's suit and blazer sizes between US/UK, EU and Italian from chest, height and drop.GBP to USDConvert British pounds to US dollars at the daily ECB reference rate, with a 30-day chart.Hat Size ConverterConvert head circumference to US, UK and EU fitted hat sizes and S–XXL, with kids' sizes.Jeans Size ConverterConvert jeans sizes between W/L waist inches, women's US, UK, EU and S–XL for men and women.Kids Clothing Size ConverterConvert kids' clothing sizes between US 2T–16, UK age and EU height sizes by height and weight.Knitting Needle Size ConverterConvert knitting needle sizes between US, metric mm and old UK, with yarn weight suggestions.Lumber Size ConverterConvert nominal lumber sizes (2×4, 4×4, 1×6…) to actual dimensions in inches and mm.Men's to Women's Shoe SizeConvert men's shoe sizes to women's (and back) in US, UK and EU, with foot length.Metric Prefix ConverterConvert between SI prefixes (nano, micro, milli, kilo, mega, giga…) for any unit.mg/dL to mmol/LConvert glucose, cholesterol and triglyceride results from mg/dL to mmol/L.Mixed Number to Improper FractionConvert mixed numbers to improper fractions and back, with steps and a pie model.mmol/L to mg/dLConvert glucose, cholesterol and triglycerides from mmol/L to mg/dL with reference ranges.