Check out Nikolaj Poulsen's thread in the Tips & Tricks group on the blog. He has a section where he talks about this. I think he was looking mostly at two handed weapons, but his data and findings will answer most, maybe all, of your questions.
For reference, using his given formulas, at 100 Block with 5/5 Shield Wall, you stop 75% of damage while blocking with any weapon. Bash damage is based on your weapon's base damage (i.e., before perks, enchantments, and other buffs are factored into its listed damage). So a daedric greatsword would bash for significantly more damage than an iron dagger. He also notes that Deadly Bash and Power Bash stack, for a total of 15x bash damage. So with a daedric greatsword, 100 Block, and both bash perks, you bash for an impressive 108 damage.
Don't thank me, thank Nik. He's the one who did all the work! In case you missed it, I edited my previous comment with some sample calculations. Ultimately, I think the answer to your question is that, yes, blocking (and bashing) with one handed weapons can be very effective.
One more example that may be more specific to your case: at 100 Block, 5/5 Shield Wall, when using a one handed weapon with base damage of 11 (Blades Sword, Scimitar, Nord Hero Sword, Skyforge Steel Sword, Elven Sword, Nordic Sword), you absorb 75% of physical damage while blocking, and you bash for 49 damage.
It's also worth noting that you can still benefit from such perks as Quick Reflexes and Shield Charge while blocking one handed weapons, though Shield Charge only works for small bursts, rather than indefinite sprinting as with shields. Henson's Ka Po Tun build does this with two handed weaponry, and it's obviously very effective. So yeah, you can easily make a strong character built around blocking with one handed weapons.
I am wondering if I did my math wrong, but it seems that taking any block perks is unnecessary when using a one handed weapon blocker, as with out any of the shield wall perks you should hit 75% not counting in their weapon damage, and if they have a 20 damage weapon at base it does nothing?
I used the following formula (from , but cheated with some algebra to avoid needing the enemies base weapon damage.
Blocked Damage Values Depending on Skill rather than Enemy Weapon
Block Skill Skill Modifier % blocked
20 1.3 39%
30 1.45 43.5%
40 1.6 48%
50 1.75 52.0
60 1.9 57
70 2.05 61.5
80 2.2 66
90 2.35 70.5
100 2.5 75
Blocked Damage % = { 30 + 0.2 x EnemyWeaponBaseDamage x [ 1.0 + (BlockSkill/100) x 1.5 ] } x (1 + Shield Wall perk) x (1 + Enchantment#1 + Enchantment#2) x (1 + Potion)
Here is how I did the math...
[1.0 + (Block Skill/100) * 1.5] = Skill modifier
30 = Base Block Value
0.2 * Enemy Weapon base Value = Enemy Modifier
Totals: 30 * Skill Modifier + (Enemy Modifier * Skill Modifier) =
On higher difficulties Blocking is a must, especially if you have gimped your character (no magic use) you can stave off up to 80% of incoming damage, however shield bashing on master difficulty offers very little to nothing for players, you will also find (if you would care to look) that most, if not all builders perk the block skill tree heavily to negate incoming damage, so in my humble opinion yes Blocking is worth all the perks you invest into it, apart from the bashing perks on higher difficulties.