What a Defence Upgrade Is Actually Worth at Your Town Hall
Updated: 18 September 2026 · Goblins Farm
Everyone tells you to upgrade defences. Almost nobody tells you what an upgrade buys, and the answer changes by a factor of eighteen across the game. We took every defence level in the game files, divided the damage it adds by the builder time it costs, and grouped the results by Town Hall. The curve is steep, consistent, and it ought to change how you queue builders.
The curve
Damage-per-second gained per builder-day spent, summed across every defence upgrade unlocked at each Town Hall:
- TH8 — 19.3 DPS per builder-day (13 upgrades, 6.0 builder-days, 8.6M gold)
- TH9 — 11.5 (10 upgrades, 10.0 days, 12.2M gold)
- TH10 — 7.1 (14 upgrades, 16.8 days, 20.3M gold)
- TH11 — 4.4 (16 upgrades, 29.8 days, 40.1M gold)
- TH12 — 4.1 (13 upgrades, 30.2 days, 45.4M gold)
- TH13 — 4.1 (16 upgrades, 51.0 days, 73.8M gold)
- TH14 — 4.1 (11 upgrades, 47.0 days, 73.5M gold)
- TH15 — 2.1 (14 upgrades, 78.5 days, 106.2M gold)
- TH16 — 2.4 (12 upgrades, 81.0 days, 114.0M gold)
- TH17 — 1.8 (14 upgrades, 114.5 days, 218.3M gold)
- TH18 — 1.1 (14 upgrades, 193.2 days, 317.4M gold)
The same fortnight of builder time buys eighteen times less defence at Town Hall 18 than at Town Hall 8. Per million gold the collapse is worse: 13.6 DPS at Town Hall 8, 0.66 at Town Hall 18 — a factor of twenty.
Why the numbers get worse and the bases get harder
Both things are true at once, and they are not contradictory. A defence upgrade at Town Hall 18 adds almost nothing to that defence's damage — the top Air Defence level adds 50 DPS for 26 million gold and 13.2 days — but late Town Halls add entirely new defences, more of each defence, and large hitpoint increases that this measure deliberately ignores.
What the curve really shows is where a builder-day is cheap. At Town Hall 8, defence upgrades are the best thing a builder can be doing, because the same day of work will never buy that much damage again. At Town Hall 17 and 18, an individual defence level is close to a rounding error, and what your builders are actually buying is hitpoints and the completion bonus of a finished base.
The practical rule this produces
Below Town Hall 11: upgrade defences aggressively and in bulk. They are cheap, fast, and each one is a meaningful fraction of the base. This is also the range where rushing costs the most, because the upgrades you skip were the efficient ones — see how not to rush.
Town Hall 11 to 14: defences and offence compete, and offence wins. Four DPS per builder-day is real but unremarkable, and a laboratory research or hero level in the same fortnight does more for your account, because attacking earns resources and defending does not.
Town Hall 15 and up: upgrade defences to finish them, not to improve them. At one DPS per builder-day the individual upgrade has stopped mattering. What matters is that every defence is done, because it is the aggregate that decides whether a base holds.
The defence that breaks the pattern
Two do, in opposite directions. The Monolith and the Revenge Tower cost hundreds of thousands of gold rather than tens of millions, which makes them the only defences at high Town Halls whose gold price is not the constraint — build time is.
Going the other way, the Eagle Artillery reads as 50 DPS in the files, which would make it the worst defence in the game if the number meant what it appears to mean. It does not: the Eagle fires in volleys at deployed troops after a housing-space threshold is crossed, and a per-second average is the wrong unit for it. The same caution applies to the Inferno Tower's single-target mode and to anything with a charge-up. This is why the analysis above aggregates across all defences at a Town Hall instead of ranking individual buildings — the aggregate is robust to those quirks, a league table is not.
How we counted
For every defence in the game files we took each level's damage-per-second, subtracted the previous level's, and divided the total gain at each Town Hall by the total build time of those upgrades. Build time is in builder-days: one builder working one day. Gold is the raw build cost with no Gold Pass discount, no hammers and no potions.
Deliberately excluded: hitpoints, splash radius, range, trap upgrades and walls. Walls in particular would distort everything, since they cost 11.2 billion gold and no builder time at all.
Frequently asked
Which defence should you upgrade first in Clash of Clans?
Below Town Hall 11, whichever is cheapest and fastest — defence upgrades there buy 7 to 19 DPS per builder-day, the best rate in the game. From Town Hall 15 up, individual defence levels buy around 1 to 2 DPS per builder-day, so the goal becomes finishing every defence rather than choosing between them.
Are defence upgrades worth it at high Town Halls?
Individually, barely: at Town Hall 18 a defence upgrade buys 1.08 DPS per builder-day and often costs 26 million gold for 13 days. Collectively they still matter, because late upgrades add hitpoints and new buildings that this measure ignores. They are simply no longer the best use of a builder-day compared with offence.
Should you upgrade defence or offence first?
Offence, from roughly Town Hall 11 onward. Attacking earns resources and defending does not, and from Town Hall 11 a defence upgrade buys about 4 DPS per builder-day against the compounding return of a better army.
Keep reading
Goblins Farm is not affiliated with, endorsed by, sponsored by, or specifically approved by Supercell. Clash of Clans is a trademark of Supercell Oy. This material is unofficial fan content produced under Supercell's Fan Content Policy. Game values change with every update; always verify in-game before committing an upgrade.