How Old was David when He Killed Goliath?

One of the most beloved stories in the Bible is that of young David taking on the giant, Goliath, before he became king. It is easy for most people to identify with this story, not because they have faced off against a physical giant, but because we all have giants in our lives that we feel we have to battle every day. While those might not be physical giants, like David faced, they are big enough to make us feel small… and that’s all that really matters.

It is how David dealt with Goliath that made him famous. Even though he was a young man, he faced up to a giant that older men, with more experience in battle, were afraid to fight. That made him a hero, not only to the people of that day, but to people ever since. Just how old was he, when that happened. 

It’s not all that easy to pin down David’s age at the time of that fight. The Bible tells us several things about his life; but most of that is later on, when he was king. This obviously happened before then, while Saul was still king. At the same time, we know that it happened after Samuel had anointed David to be king; so, we should be able to narrow it down. 

What’s the Big Deal About Fighting Goliath?

Before looking at the chronology of David’s life, it would help us in our understanding of this event, if we had a better picture of Goliath. We find very little mentioned about him in the Bible, other than in chapter 17 of 1 Samuel, where he fought David. In that chapter, he challenged the army of Israel to send out a champion to fight him. 

To set the scene, we find that the armies of Israel and the Philistines were gathered at Sochoh, in the territory of Judah, to fight. The army of Israel was gathered in their battle array on the mountainside on one side of the Valley of Elah, and the army of the Philistines were gathered across the valley from them, on another mountainside (1 Samuel 17:1-3). 

And a champion went out from the camp of the Philistines, named Goliath, from Gath, whose height was six cubits and a span. 5 He had a bronze helmet on his head, and he was armed with a coat of mail, and the weight of the coat was five thousand shekels of bronze. 6 And he and bronze armor on his legs and a bronze javelin between his shoulders. 7 Now the shaft of his spear was like a weaver’s beam, and his iron spearhead weighed six hundred shekels; and a shield-bearer went before him. – 1 Samuel 17:4-7

There are a lot of details in those verses, not all of which we are going to look at. But the first thing that stands out was Goliath’s huge size. The Biblical measure of a span is the distance from a man’s elbow to the tip of his middle finger; and that of a span is the distance from the tip of the thumb to the tip of the pinkie, with the hand spread as far as possible. While this can obviously vary, depending on the size of the man, a cubit is normally understood to mean 18” and a span to mean 9”. Based on that, Goliath is 9’ 9” tall. Some people define the cubit as 20”, which would make Goliath even bigger. So, if we go with the 9’ 9” figure, we’re going with a more conservative estimate.

But could there have been giants in the world back then? The Bible makes reference to The Nephilim in Genesis 6:4, saying: 

“There were giants on the earth in those days, and also afterward, when the sons of God came in to the daughters of men and they bore children to them. Those were the mighty men who were of old, men of renown” (Genesis 6:4).

While this was before the flood and the Bible doesn’t give a clear definition of the word “giant,” we can safely take the common understanding of this word. Even though Noah and his sons were not of these giants, the genetics existed for giants to exist and even exists today. One need only look at Robert Wadlow, who lived from 1918 to 1940 and was 9’ 5” tall to realize that the possibility of Goliath being a true giant existed. 

The passage then goes on to define Goliath’s armament for us, which was a combination of bronze and iron. This shows us that this event took place at a time when the world was transitioning from the bronze age to the iron age, as he had weapons of both. The weight of his coat of mail works out to 156 pounds, 4 ounces. To put that in perspective, a coat of chainmail, such as the type used in the Middle Ages, weighed 55 to 60 pounds. With Goliath’s huge size, the extra weight wouldn’t have been a problem. As for weapons, we know that he carried a shield, a spear, a javelin, and a sword, as all of these are mentioned in scripture. The spearhead alone weighed 18 pounds, making it over eight times as heavy as the Roman Gladius (sword) that was used in New Testament times.

As for the man himself, we find that King Saul refers to him as having been “a man of war from his youth” (1 Samuel 17:33b). That makes it seem that not only was he a warrior, but he had trained to be a warrior all his life. He didn’t just depend on his huge size and strength in battle, but had the necessary knowledge to use his weapons effectively. 

We also know that Goliath had at least one brother, who was apparently also a giant. In 2 Samuel 21:19 and 1 Chronicles 20:5, the Bible makes reference to a man named Elhanan, the son of Jair, from Bethlehem, killing Lahmi, the brother of Goliath. As with Goliath, his spear’s shaft was described as being “like a weaver’s beam.” 

Goliath’s Challenge

We are told there, in chapter 17 of 1 Samuel, that Goliath went out before the army of the Philistines to challenge the army of Israel, as was common in the day. Anyone who has seen the Movie Troy, with Brad Pitt as Achilles, will have seen such a challenge, early on in the movie, when he defeats a champion for the king Agamemnon, who he despises. 

Then he (Goliath) stood and cried out to the armies of Israel, and said to them, “Why have you come out to line up for battle? Am I not a Philistine, and you the servants of Saul? Choose a man for yourselves, and let him come down to me. 9 If he is able to fight with me and kill me, then we will be your servants. But if I prevail against him and kill him, then you shall be our servants and serve us.” 10 And the Philistine said, “I defy the armies of Israel this day; give me a man, that we may fight together.” – 1 Samuel 17:8-10

Of course, considering how big Goliath was, the Philistines were stacking the deck against Israel. Some ministers have said that he wanted Saul to come fight him, as Saul was head and shoulders above the average man; but we don’t actually know what he was thinking. All we know is that it was David who accepted the challenge. 

Just Who Was David?

We know quite a bit about David now; but at the time of this battle, there was little to be known about him. Samuel had anointed him to be king, but he had not yet taken that mantle. Other than his family, who saw Samel anoint him, it is unlikely that anyone knew what had happened (1 Samuel 16:13). His brothers apparently didn’t think much of him being anointed to be king, because they mocked him, in typical sibling rivalry, when he showed up at the battle (1 Samuel 17:28). 

But David was known to King Saul, although it is unlikely that Saul knew that David had been anointed to replace him as king. In the latter half of chapter 16, David served in the palace, playing the harp when Saul was troubled by an evil spirit (1 Samuel 16:22-23). He impressed Saul so much that Saul made him his armor bearer. 

This gives us a bottom end for David’s age at 20, as God had established in the law that young men had to be at least 20 years of age to go to war (Numbers 1:3). As the position of being an armor bearer was a military position, requiring that he would go to war with Saul, David had to be at least 20 years old. 

Actually, the armor bearer did more than what we might imagine. While the idea to us is more like that of a page, one who carried and cared for his Lord’s armor and arms, in that time, the armor bearer also had the responsibility of standing back-to-back with their Lord, in this case the king, and protecting his back. Apparently, David had been trained to be quite a warrior himself, for Saul to choose him to serve in this critical position. That training could very well have happened during the time that David was serving the king in the palace. 

Looking a little further, we find that David was given officer rank in the army of Saul, even high rank, as one of Saul’s generals; perhaps even his chief general. 

So David went out wherever Saul sent him, and behaved wisely And Saul set him over the men of war, and he was accepted in the sight of all the people and also in the sight of Saul’s servants. – 1 Samuel 18:5

So the women sang as they danced, and said: “Saul has slain his thousands, and David his ten thousands.” – 1 Samuel 18:7

How quickly did David rise in rank? The Bible gives us no idea. There is nothing to say that David went off and fought in a single battle. Other than against Goliath, before the verse above where King Saul set him over the men of war. Saul already had a commander for his army, named Abner, so it is unlikely that David instantly became the commander. Besides, he would have to prove himself as a leader in battle, more than just killing Goliath, before the soldiers in the army would be willing to follow him. Likewise, he would not have a reputation of killing “tens of thousands” from only one battle. 

Closing the Other End of the Time Scale

With 20 as a bottom end of the time scale, we need to find a top end as well. Samuel records that for us as well, telling us when David was crowned king. 

David was thirty years old when he began to reign, and he reigned forty years. 5 In Hebron he reigned over Judah seven years and six months, and in Jerusalem he reigned thirty-three years over all Israel and Judah. – 2 Samuel 5:4-5

So, now we have things narrowed down to a gap from 20 years of age, to 30; actually, more than 20, but we don’t know how much more. Can we narrow it down more? Yes. There was a time when King Saul turned against David and wanted to kill him, brought about by his own jealousy for David, because of the women ascribing tens of thousands to David, while only crediting himself with thousands. David fled to the wilderness, after King Saul tried to kill him with a javelin (1 Samuel 18:8-11). It didn’t happen immediately, as we see David married Saul’s daughter, Merab, in the last half of 1 Samuel, chapter 17, but he nevertheless fled. Ultimately, Merab, and her brother Johnathan, helped David escape from their father’s wrath. 

The Bible doesn’t tell us just when Saul did this; but we know that it was after David defeated Goliath and after he became a general in Saul’s army. That would indicate at least a few years, if not several. 

There are several places where David went, after fleeing from Jerusalem, during the time he was trying to keep away from Saul. Nevertheless, the king was relentless in seeking after David, with the clear intent of killing him. Ultimately, David fled to the land of the Philistines, where he and the 600 men who followed him were given the town of Ziklag to live in. We know from 1 Samuel 27:7 that David dwelt there for 1 year and 4 months. 

This narrows our window a bit more. In the chronology of David’s story, as shown in the Bible, there was a lot that happened in David’s life in the 10 years between his 20th and 30th birthdays. The key thing though, is that pretty much all of it seems to have happened after his fight with Goliath. So, while David had to be at least 20 years old to be King Saul’s armor bearer, he didn’t have to be much older than that. It is likely that his fight with Goliath was close to that age; probably between 21 and 23 years of age. As further evidence of this, Goliath scorned his youth, when David ran to the battle. 

And when the Philistine looked about and saw David, he disdained him; for he was only a youth, ruddy and good looking. – 1 Samuel 17:42

Perhaps Goliath wouldn’t have been so disdainful of David, had he but heard what David had said to Saul, before going off to the battle:

But David said to Saul, “Your servant used to keep his father’s sheep, and when a lion or bear came and took a lamb out of the flock, 35 I went out after it and struck it, and delivered the lamb from its mouth; and when it arose against me, I caught it by its beard and struck and killed it. 36 Your servant has killed both lion and bear; and this uncircumcised Philistine will be like one of them, seeing he has defied the armies of the living God.” 37 Moreover David said, “The Lord, who delivered me from the paw of the lion and from the paw of the bear, He will deliver me from the hand of the Philistine.” – 1 Samuel 17:34-37a

Saul tried to press his own armor and sword on David, but David chose to go to battle with nothing more than a sling (not a slingshot) and a stick. He took five smooth stones as ammo for his sling; but needed only one. But he also went in the name of the Lord. With one hurl from his sling, he killed the giant, hitting him in the forehead with such force that the stone broke through the skull and sank into his head, apparently killing him instantly (1 Samuel 17:49). Just to be sure, David drew Goliath’s sword and cut his head off with it (1 Samuel 17:51).