The Washington area's economy has been wrenched askew by the wildcat transit workers' walkout, which already appears to have caused hundreds of thousands of dollars of financial damage to downtown businesses, wage earners and the District of Columbia government.

Major downtown department stores have reported substantial sales decreases since the strike started last Wednesday. Some restaurants, including those located near Metro subway stops, drew significantly fewer lunch-time customers than usual. Nevertheless, other commercial enterprises profited from the strike, as parking lots were crowded and service stations sold more gas than usual to commuters who could no longer ride to work by bus or subway.

The District of Columbia government lost an estimated $10,000 a day in parking revenue because of its decision to let parking meters go unused during the Metro walkout. The D.C. government also spent $50,000 more than usual in overtime pay for additional police who were needed chiefly to contend with traffic congestion, according to police spokesmen.

The largest group of workers who lost wages during the strike appears to have been the more than 4,000 Metro employes who stayed off their jobs. Uncounted numbers of other wage earners, especially low-income and handicapped persons, also found themselves unable to get to work during the strike and will receive reduced paychecks.

For Metro employes who joined in the wildcat walkout, lost earnings may be substantial. Starting bus drivers are currently paid about $53 a day, according to Metro officials. Drivers who have worked for Metro for 2 1/2 years or more average about $70 a day in wages. Among mechanics, Metro officials say, typical earnings vary from about $75 to $85 a day.

These workers' probable losses in income appear to overshadow any financial gain the strike may bring them in their main point of contention - Metro's failure to pay its employes an immediate 20-cents-an-hour, cost-of living increase. For a typical, veteran bus driver, this escalator would add only about $1.75 to his daily earnings.

The transit agency - the primary target of its employes' angry protest - appears likely to be among the financial beneficiaries of the strike. Because the transit authority normally operates at a deficit, a halt in bus and subway service sharply cuts its daily losses despite the loss of fares.

How much money the transit agency and the local governments that help subsidize it will save because of the walkout is as yet unclear. Figures provided yesterday by Metro officials show that the authority normally runs a deficit of considerably more than $300,000 a day. Metro, nonetheless did not break even during the walkout, officials noted, because some nonstriking employes must still be paid and because the transit agency collected virtually no revenue.

The strike's impact fell heavily on downtown department stores, some of which had previously reported increased business stemming from the opening and expansion of Washington's two-year-old subway system. Top officials at Woodward & Lothrop, Garfinckel's, the Hecht Co. and Morton's Department Stores all reported sales drop, in varying degrees, at their downtown shops because of the strike.

"It's had a very serious effect on downtown," said Edwin K. Hoffman, board chairman of Woodward & Lothrop. He described sales at the downtown store, located above the Metro Center subway stop at 11th and G Streets NW, as off by as much as 40 percent compared with a year ago. Before the strike, Hoffman noted, the downtown store had been doing significantly more business than last year.

Mortimer C. Lebowitz, president of Morton's stores, which specialize in moderately priced family apparel, said the transit strike had cut sharply into sales at all three Morton's stores in central Washington, possibly reducing business by more than 40 percent. In addition, he said, the walkout had disrupted preparations for Morton's back-to-school promotion, scheduled to begin early next month.

"I could think of a dozen different things," Lebowitz said, as he complained of economic damage the strike had caused. "The cost to the innocent bystander is incalculable."

The transit walkout's impact on Washington's restaurant business was not confined to the downtown area, because an increasing number of downtown workers has started lunching at outlying dining spots that now can be reached by subway. Such lunchtime ventures were curtailed by the strike.

At Tom Sarris' Orleans House, near Metro's Rosslyn subway stop, lunchtime business dropped by about 15 percent because of the transit strike, Frank Sarris, the beef and seafood restaurant's general manager, said during a telephone interview. He added that several small banquet groups canceled their luncheon plans because they had no way to get to the restaurant from the downtown area.

At Hugo's rotisserie in the Arlington Hyatt House Hotel, Oscar Carcamo, the restaurant's manager, said he quickly recognized the effects of the transit strike because he stopped seeing some familiar lunchtime faces - those of previously steady customers who normally came by subway from Georgetown and Foggy Bottom. "We haven't seen them in the last few days," Carcamo said.

For parking lot owners, the transit strike appears to have had both pluses and minuses. Many made money because of extra customers, but they also had to pay their regular employes additional overtime compensation and bring in extra part-time workers to handle the surge in auto commuters. Moreover, some parking officials argued that the all-day commuters reduced turnover at their lots - a factor that normally accounts for additional revenue.

"It was more headaches than it was worth," said an official of PMI, the Washington area's biggest parking lot operator.