Florence Cathedral facts at a glance
Santa Maria del Fiore is the cathedral of Florence, on the Piazza del Duomo. Walking into the cathedral itself is free and needs no reservation. The dome, the bell tower, the baptistery, the museum and the ruins of Santa Reparata are separate visits that need a pass. See Duomo tickets and passes for the three passes and their 2026 prices.
This page collects the figures visitors search for. Several of them describe different points of the same building, so each one is listed with what it measures. That avoids the common mix-up between the width of the dome, the height to the lantern and the height of the whole structure.
The numbers, and what each one measures
Figures for 2026. Rounded where the text says so.
| Item | Figure | What it means |
|---|---|---|
| Dome, inner diameter | 45.5 m | Octagonal double shell, measured inside |
| Dome, outer diameter | 55 m | Measured on the outer shell |
| Floor to base of the lantern | 90 m | From the cathedral floor to the foot of the lantern. It is not the height of the whole building and not the height of a viewing platform |
| Cathedral length | 153 m | Length of the cathedral |
| Transept width | 90 m | Width of the transept |
| Dome climb | 463 steps | No lift. Entrance at the Porta della Mandorla on the north side, about 45 minutes |
| Giotto's Bell Tower | 84.7 m (about 85 m) | The rounded figure is the one on pass pages |
| Bell tower climb | 414 steps | No lift. Loggias on the way and a terrace at the top |
| Cathedral terraces | about 32 m high, 150 steps | Guided visit only, no lift, no bags |
| Dome fresco | 3,600 m² | The Last Judgment painted inside the dome |
| Museo dell'Opera del Duomo | over 6,000 m² | 28 rooms on 3 floors |
For most visitors the useful numbers are 463 steps for the dome and 414 for the bell tower. Both are stairs without a lift, so decide early which climb you want. The dome climb page and the bell tower page cover the rules.
Our pick: see the dome up close
Our take: climbing between the two shells shows you the size of the dome up close.
Hand-picked tours, booked through GetYourGuide. Prices are indicative starting prices in euros (as of October 2026). Tap a tour for live availability and the current price in your currency.
Florence Duomo tours and passes
Guided visits of the dome, the cathedral and the baptistery with museum, with live prices and availability.
How the dome is built
Brunelleschi's dome is an octagonal double shell. Bricks are laid in a herringbone pattern, and the outer shell is covered with terracotta. The stairs of the climb run in the space between the two shells.
The builders worked without continuous wooden centering. The dome was built from 1420 to 1436. The history page puts that into the longer story of the cathedral.
Marble colours and the brick estimate
The cathedral and the bell tower use white, red and green marble. The baptistery uses white and green. Together the three buildings form the ensemble you see on the square.
A rough estimate from 2020 puts the dome at more than 4 million bricks and about 28,000 tonnes. Treat that as an estimate, not a count. Higher figures for the overall height of the structure use a different reference point than the 90 m to the lantern base.
For views of the dome from the other side of the river, see the photo spots in Florence.
Facts that are easy to mix up
Four points that are easy to mix up.
Who painted the dome
The Last Judgment inside the dome was painted by Giorgio Vasari and Federico Zuccari between 1572 and 1579. Michelangelo's Pietà Bandini is in the museum, not in the dome.
Inside the cathedral →Who built the bell tower
Work began in 1334 under Giotto. After his death Andrea Pisano continued it, and Francesco Talenti finished it in 1359. Giotto did not build the whole tower.
Giotto's Bell Tower →Original doors
The Gates of Paradise are the eastern door of the baptistery by Lorenzo Ghiberti, with 10 Old Testament panels. The originals of the bronze doors are kept in the museum.
Museo dell'Opera del Duomo →Free versus paid
The cathedral interior is free. Dome, bell tower, baptistery, museum and Santa Reparata are covered by the three passes, which are valid for 3 calendar days.
Tickets and passes →
Florence Cathedral facts: frequently asked questions
How wide is the dome of Florence Cathedral?
The inner diameter is 45.5 m and the outer diameter is 55 m. It is an octagonal double shell with the stairs between the two layers.
How tall is the cathedral?
The figure that is clearly defined is 90 m from the cathedral floor to the base of the lantern. Taller numbers for the whole structure count to a different point, so compare them with care.
How many steps are there to the top?
463 steps to the dome and 414 steps up Giotto's Bell Tower. Neither has a lift. The terraces, which are visited only with a guide, have 150 steps.
How many bricks does the dome contain?
Only estimates exist. One estimate from 2020 speaks of more than 4 million bricks and about 28,000 tonnes, and it should be read as an estimate only.
Is the cathedral free to enter?
Yes, the cathedral interior needs no ticket and no reservation. Dome, bell tower, baptistery, museum and Santa Reparata are paid visits. Dress rules apply: cover shoulders and knees and avoid flip-flops.
Is cathedralofsantamariadelfiore.com the official site of the cathedral?
No. This is an independent visitor guide with no link to the cathedral, the cathedral foundation, the museum or the city of Florence.