Pike and shot
The Spanish average throughout the 16th century was 2 pikes for every 1 firearm.
In the 1570s the standard infantry company in Dutch service (whether they be Dutch or foreign hires such as Germans and English) had about 150 men, including 4 officers (a captain, lieutenant, quartermaster, and barber-surgeon), 5 NCOs (two sergeants and three corporals), 15 musketeers, 65 arquebusiers, 45 pikemen, 12 halberdiers and targeteers, and 3 musicians (two fifers and a drummer). A study of a selection of Dutch companies from 1587, standardized by William of Orange, showed 34% pikes, 9% halberds, 5% swords and bucklers, and 52% firearms. Bucklers disappeared from the ranks by the end of the 16th century, as did halberds except in the hands of NCOs and bodyguards.
In 1588, the English Trained Bands consisted of 36% arquebusiers, 6% musketeers, 16% bowmen, 26% pikemen, and 16% billmen. Lansdowne MS 56, attributed to Lord Burghley, states that ideally infantry formations should consist of 50% shot, 30% pikes, and 20% billhooks.
In 1571 the Ming Chinese general Qi Jiguang wrote a military manual outlining his ideal compositions for military formations. In regards to missile weapons, an infantry brigade of 2,699 men was to be equipped with 1,080 matchlock arquebuses and 216 bows (40% firearms). A cavalry brigade of 2,988 men was to be equipped with 1,152 bows, 432 arquebuses, and 60 "crouching tigers", miniature bombards loaded with one hundred pellets each, essentially 21.6 kg blunderbusses (20% firearms). A wagon brigade of 3,109 men was equipped with 145 wagons, 256 swivel guns manned by two men each, and 512 arquebuses (33% firearms), plus eight proper cannons. On paper these were roughly in line with contemporary European rates but it is not known if these proportions were ever reached in practice.
In 1601, Spanish regiments in the Low Countries were 44% pikes and 56% muskets and arquebuses. German ones had far fewer firearms, with 79% pikes to 21% arquebuses and muskets. Proportions changed, and by 1625 the field infantry of the German Catholic League were 58% muskets and arquebuses, 36% pikes, and 6% halberds; this changed again in 1627 to 65% muskets, 20% pikes, and 15% halberds. The ideal field ratio often deviated from the usual combat experience; skirmishes, sieges, and minor actions were far more common than large pitched battles, and pikes were not as useful in these engagements due to the pike's low value as a personal weapon (indeed, in the English Civil Wars, only 15% of battle deaths occurred in major battles, whereas nearly half occurred in battles with fewer than 250 total casualties). In 1632, the Spanish army standardized their infantry companies at 68% arquebuses and muskets and 32% pikes.
Contemporary Japanese units, while heavily focused on firearms by East Asian standards, had higher ratios of other weapons to arquebuses compared to late 16th to early 17th century European formations. When Japan invaded Korea in 1592, 30% of Japanese soldiers had firearms, and the rest were equipped with pikes, swords, and bows. Firearms usage declined after 1603.
In 1618–1629, the pike to shot ratio fluctuated between 1 and 2 muskets per pike for various Western European armies. 1631–1632 saw an increased proportion of firearms, with some formations being more than 80% gunmen. The standard in the Imperial Army of the Holy Roman Empire in 1641 was 66% muskets and 33% pikes. As pike-on-pike clashes became less common in field battles, so did armor. By 1660 body armor had mostly disappeared in pike and shot formations; the pikes themselves had also shortened, from 18 feet to 13 feet.  During the English Civil Wars (1642–1651), both sides preferred 2 guns to 1 pike, though this ratio was flexible.
At the 1683 Battle of Vienna, the Imperial Army had set its infantry companies at 61% firearms, 33% pikes, and 6% shieldmen. The English army of the Nine Years War in the 1690s still had 2 muskets for every 1 pike. Meanwhile, by 1687, the French army's ratio was set at 75–80% muskets and 20–25% pikes.
At the start of the Great Northern War in 1700, Russian line infantry companies were 83% muskets and 17% pikes. The musketeers were initially equipped with sword-like plug bayonets; they did not fully switch to socket bayonets until 1709. A Swedish infantry company at the start of the war consisted of 66% muskets and 33% pikes. While they all carried swords, Swedish musketeers were not completely equipped with bayonets until 1704.
The rapidly rising percentage of firearms spurred by pike-and-shot battles, until reaching near-100% by the 18th century, was generally not mirrored in non-European countries that did not adopt such tactics. Nor was the proliferation of the flintlock; matchlocks remained the most common firearms in India, China, and Southeast Asia until about the mid-19th century due to being far less complicated to manufacture. For example, by the mid-17th century, only 10–13% of Javanese soldiers used firearms, and by the 1680s, 20% of Thai soldiers used firearms. By 1825, 50% of Burmese soldiers had firearms, and as late as 1858, only 15% of the Vietnamese soldiers summoned to fight the Cochinchina campaign had firearms. By the 1840s, only 30–40% of Chinese soldiers had firearms (all matchlocks), the rest being armed with spears, swords, and bows.

Spanish and Imperial developments: The armies of Charles V, Holy Roman Emperor and King of Spain, further developed the pike and shot formation. The front line of Charles' German Landsknechte consisted of doppelsöldner, renowned for their use of arquebus and zweihänder during the Italian wars. The Spanish colunellas continued to show valuable flexibility as the Italian Wars progressed, and the Spanish string of battlefield successes continued. The colunellas were eventually replaced by the tercios in the 1530s by order of Charles. The tercios were originally made up of one-third pikemen, one-third arquebusiers and one-third swordsmen. Tercios were administrative organizations and were in charge of up to 3000 soldiers. These were divided into ten companies that were deployed in battle. These companies were further subdivided into small units that could be deployed individually or brought together to form great battle formations that were sometimes called "Spanish squares". 
As these squares matured in usage during the 16th century, they generally took on the appearance of a "bastioned square" – that is, a large square with smaller square "bastions" at each corner. The large square in the center was made up of the pikemen, 56 files across and 22 ranks deep. The outer edges of the central pike square were lined with a thin rank of arquebusiers totaling 250 men.  At each corner of this great pike square were the smaller squares of arquebusiers, called mangas (sleeves), each 240 men strong.  Finally, two groups in open order, each of 90 men and armed with the longer musket, were placed in front of, and to the sides of, the arquebusiers. 
Normal attrition of combat units (including sickness and desertion) and the sheer lack of men usually led to the tercios being far smaller in practice than the numbers above suggest but the roughly 1:1 ratio of pikemen to shooters was generally maintained. The tercios for all armies were usually of 1,000 to 2,000 men, although even these numbers could be reduced by the conditions already mentioned. Tercio-type formations were also used by other powers, chiefly in the Germanic areas of the Holy Roman Empire.
To modern eyes the tercio square seems cumbersome and wasteful of men, many of the soldiers being positioned so that they could not bring their weapons to bear against the enemy. However, in a time when firearms were short-ranged and slow to load, it had its benefits. It offered great protection against cavalry – still the dominant fast-attack arm on the battlefield – and was extremely sturdy and difficult to defeat.